High-Thermal- and Air-Stability Cathode Material with Concentration

Subscriber access provided by READING UNIV

Article

A High Thermal and Air Stability Cathode Material with Concentration-Gradient Buffer for Li-Ion Batteries Ji-Lei Shi, Ran Qi, Xu-Dong Zhang, Peng-Fei Wang, Weigui Fu, Ya-Xia Yin, Jian Xu, Li-Jun Wan, and Yu-Guo Guo ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.7b14684 • Publication Date (Web): 17 Nov 2017 Downloaded from http://pubs.acs.org on November 20, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Applied Materials & Interfaces is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

A High Thermal and Air Stability Cathode Material with Concentration-Gradient Buffer for Li-Ion Batteries Ji-Lei Shi, †,‡,# Ran Qi, †,§,# Xu-Dong Zhang, †,‡ Peng-Fei Wang, †,‡ Wei-Gui Fu,§ Ya-Xia Yin,*,† Jian Xu, †,‡ Li-Jun Wan, †,‡ Yu-Guo Guo*,†,‡ †

CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS

Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, P. R. China. ‡

University of Chinese Academy of Sciences, Beijing 100049, P.R. China.

§

State key Laboratory of Separation Membranes and Membrane Processes, School of

Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300071, P. R. China

KEYWORDS

Li-ion batteries, cathode materials, Ni-rich, thermal stability, concentration gradient

1 ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 26

ABSTRACT

Delivery of high-capacity with high thermal and air stability is a great challenge in developing of Ni-rich layered cathodes for commercialized Li-ion batteries (LIBs). Herein we present a surface concentration-gradient spherical particle with varying elemental composition from the outer end LiNi1/3Co1/3Mn1/3O2 (NCM) to the inner end LiNi0.8Co0.15Al0.05O2 (NCA). This cathode material with the merit of NCM concentration-gradient protective buffer and the inner NCA core shows high capacity retention of 99.8% after 200 cycles at 0.5 C. Furthermore, this cathode material exhibits much improved thermal and air stability compared with bare NCA. These results provide new insights into the structural design of high-performance cathode with high energy density, long life span and storage stability materials for LIBs in the future.


Page 3 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1. Introduction

Challenge from energy crisis and environmental issue in the information age and mobile society has accelerated the pursue of energy storage device.1-2 High energy-density Li-ion batteries (LIBs), which have been introduced into the commercial market since 1990s and successfully applied in portable electronic devices (such as laptops and cell phones), are urgently demanded for electric vehicles (EVs) or hybrid electric vehicles (HEVs) to reduce the emissions of greenhouse gasses.3-4 Therefore, developing cathode materials, such as Ni-based layered oxides (NCA, NCM), Mn-based spinel oxides (LiMn2O4, LiNi0.5Mn1.5O4) and LiFePO4, with excellent electrochemical performance, low cost, and good safety is indispensable.5-15

However, the absence of available high-capacity cathode materials with excellent capacity retention and thermal stability has become the main bottleneck for the further application of LIBs.4 Among these cathode materials, nickel based cathode materials, as most promising cathode materials, especially LiNi0.8Co0.15Al0.05O2 (NCA), for realizing the bright future of LIBs was widely studied and even practically applied in Panasonic batteries for Tesla pure EVs due to their high specific capacity.16-24 But some inherent disadvantages of NCA, such as poor cycle life, poor thermal and air stability, are still needed to be improved.25-27 The poor cycle performance of NCA was mainly caused by the continuous oxygen loss from the lattice and accumulation of inactive NiO phase on the surface of the particles during charge/discharge process, which not only deteriorates the electrochemical activity of NCA, but also leads to 3 ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 26

high interfacial impedance due to its reactivity with the electrolyte. On the other hand, NCA cathode materials suffer from poor thermal stability mainly resulted from the lattice oxygen release at high temperature. Even worse, the oxygen loss usually accompanies with damage to the layered structure.28 Compared with NCA, LiNi1/3Co1/3Mn1/3O2 shows much higher thermal stability and air stability, albeit its specific capacity is slightly lower.26, 29-30 The high thermal stability and good safety characteristics of NCM benefit from the high content of stable tetravalent Mn in the material, which not only reduce electrodes and electrolytes side reactions, but also improve the structural stability.19, 31-38

Herein, we report a novel concentration gradient core-shell structure cathode material (hereafter denoted as CGCS), which combines the advantages of NCA and NCM fulfil the requirements of energy density, cycling life and storability in air. The inner core is LiNi0.8Co0.15Al0.05O2 and the outer is a concentration-gradient buffer with the concentration of Ni and Al clearly decreasing and that of Mn gradually increasing towards the surface LiNi1/3Co1/3Mn1/3O2. This core-shell structural material with concentration-gradient buffer illustrated in Figure 1a. The CGCS spherical particle is composed of varied chemical composition from the inner end NCA to the outer end NCM.

2. Experimental Section

2.1 Materials Synthesis


Page 5 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Synthesis

of

NCA.

Spherical

carbonate

precursors

(Ni0.8Co0.15Al0.05)

(CO3)0.95(OH)0.15 were synthesized via co-precipitation method. Keep the stirred tank reactor (5 L) temperature at 60 °C, 2.0 M aqueous solution of NiSO4·6H2O, CoSO4·7H2O, and Al2(SO4)3·6H2O with Ni: Co: Al = 0.8: 0.15: 0.05 was pumped into the reactor. Meanwhile, in order to maintain the pH at 8.10 of the reaction system, 2.0 M Na2CO3 aqueous solution and NH4OH solution as a chelating agent were injected into the reactor. The co-precipitated spherical powders obtained after washing, filtering and drying. The obtained (Ni0.8Co0.15Al0.05) (CO3)0.95(OH)0.15 particles were homogenously mixed with LiOH·H2O (Li/stoichiometry = 1.05) and then high temperature calcinated in a furnace, The calcination temperature was 450 °C and 800 °C for 6 h and15 h, respectively, with heating rate of 5 °C min-1.

Synthesis of CGCS. In order to construct the concentration gradient precursors, the aqueous solution of NCA (2.0 M ) (NiSO4·6H2O:CoSO4·7H2O:Al2(SO4)3·6H2O = 0.8: 0.15: 0.05) was used for the co-precipitation process. After reaction for about 0.5 h, a TM aqueous solution of NCM (Ni:Co:Mn = 1:1:1) was continuously pumped into the NCA solution. Meanwhile, homogeneously mixed solution of NCA and NCM continuously pumped into the continuously stirred tank reactor. Eventually, the carbonate precursors were washed, filtered and dried in an oven. The cathode material (CGCS) was prepared by calcinating the mixture of carbonate precursors and LiOH·H2O at the pre-sintering temperature 500 °C and 800 °C for 5 h and17 h, respectively, with heating rate of 5 °C min-1.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 26

2.2 Materials Characterization

Cathode material X-ray diffraction (XRD) patterns performed on D/max-2500 (Rigaku) equipped with Cu Kα radiation. The morphology of the particles was observed and operated at 10 kV by scanning electron microscopy (SEM) (JEOL 6701F), and the element mapping was performed on transmission electron microscopy (TEM, JEM-2100F, JEOL). The specific content of each element of the particles was analyzed by inductively coupled plasma (ICP) (Model: ICPE-9000) and an electron-probe microanalyser (EPMA).

Thermal Measurements: in order to test thermal stability of cathode materials the Differential Scanning Calorimetry (DSC) experiments were performed. The cells, Li metal as the anode, charged to 4.3 V and then disassembled in a dry box with Argon-atmosphere. After that, the obtained cathode materials (5~10 mg) with absorbed electrolyte was sealed in a high-pressure DSC container (100 µL), then it was heated from 20 °C to 350 °C with a scanning rate of 10 °C min-1 and examined by DSC(214, NETZSCH) analyzer.

2.3 Electrochemical Measurements

Electrochemical measurements performed in coin-type 2032 cells. To avoid moisture and oxygen gas, the cell assembly process must be in the argon atmosphere glove box with moisture and oxygen gas content under the 0.1 ppm. The cathodes slurries consisting of active materials (80 wt%), acetylene black (10 wt%), poly-(vinylidene

fluoride)

(PVDF,10

wt%)

and

ACS Paragon Plus Environment

a

proper

amount

of 6

Page 7 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


N-methyl-2-pyrrolidinone (NMP) was pasted on Al foil and then dried at 80 °C overnight under vacuum to obtain the working electrodes. The Celgard 2300 film as a separator to separate the cathodes and anodes. Electrolyte solution was LiPF6 (1 M) dissolved in a mixture solution of EC/DMC/DEC with the volume ratio of 1:1:1. The assembled cells tested under the voltage limits from 3.0 V to 4.3 V (vs Li+/Li) at 25 °C. The cells tested at the current density of 0.1C for 5 cycles, and then cycled at 0.5C (1C = 200 mA g−1).

3. Results and Discussion

The cathode material powders synthesized via co-precipitated method. The resultant carbonate precursors have uniform size distribution similar to NCA precursors, with D10 = 5.34 µm, D50 = 8.52 µm, and D90 = 13.5 µm according to the laser particle analyzing result (Figure S1a-b). After calcination, both of as-prepared CGCS and NCA spherical particles possess highly compact structure with a diameter of about 8 µm, promising their high density (Figure 1c and 1d).15, 29, 39 The powder XRD patterns of as-prepared CGCS and NCA were demonstrated in Figure 1b and Figure S2, respectively. The structural parameters of CGCS and NCA calculated by the Rietveld refinement method and the results were shown in table S1. From the refined results, the gradient buffer has negligible influence on the crystal parameters a and c. Moreover, Figure S3 shows the obvious peak splits of the (006)/(012) and (018)/(110), which indicates that CGCS material has α-NaFeO2 layered structure with the same structure as NCA and NCM material.40-45 And the ratio of I(003)/I(104) 7 ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 8 of 26

dramatically exceeds 1.2, indicating that few nickel ions (Ni2+) exist in the lithium layers and occupy the Li site.46 The powder XRD results show that the obtained CGCS and NCA cathode material have the perfect layered α-NaFeO2 structure without any impurity phase.

Exact

chemical

composition

of

the

resulting

particles

(CGCS)

was

LiNi0.65Co0.21Mn0.09Al0.05O2 , which was tested by the ICP (Table S2). To prove their novel concentration gradient core-shell structure, electron-probe X-ray micro-analyzer (EPMA) measurement was also applied to reveal the surface composition of the particles.

Different

from

the

ICP

result,

the

approximate

formula

is

LiNi0.61Co0.23Al0.01Mn0.15O2, indicating that the chemical composition changes from the core to the outer layer. To further visualize the detailed internal structure and confirm the gradient distribution of the elements as our design, the particles were randomly sliced by Cross section polisher (IB-19510CP), and then the cross-sectioned image

and element maps of the samples were detected by EPMA (Figure 2a).

Element maps of the cross-sectioned samples clearly show that the core within the diameter of about 6 µm maintains the constant concentration of the elements (Ni, Co and Al). The concentration of Ni and Al clearly decreases and meanwhile the concentration of Mn obviously increases towards the outmost surface of CGCS. It’s worth noting that, the central area is bright in the element map of Al, which means the high concentration of Al in the core, whereas the intensity of Al turns very weak as approaching to the out buffer, indicating the progressively decreased concentration of Al towards the outer surface.32,

40

The results of EPMA clearly confirm that the 8

ACS Paragon Plus Environment

Page 9 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


core-shell structure, where the Ni-rich core is surrounded by a concentration-gradient buffer that the concentration of the Ni and Al clearly decrease and that of Mn gradually increases towards the surface, is well developed as our design. Furthermore, the elemental distribution (Ni, Co, Mn and O) of the particles surface is tested by EDS mapping of TEM (Figure 2b).

The electrochemical performances of CGCS and NCA are demonstrated in Figure 3. As shown in Figure 3a, CGCS material delivers discharge capacity of 160 mA h g-1 with coulombic efficiency of 83.6% at the 1st cycle. After five cycles, the discharge capacity gradually increases to 165 mA h g-1 express an electrochemical activation process. The initial discharge capacity of the CGCS material is slightly lower compared with NCA (180 mA h g-1), whereas still higher than that of NCM (150 mA h g-1). The high concentration of Ni ions in the inner core is beneficial to deliver a higher capacity, and the high concentration of Mn4+ ions in concentration-gradient outer layer could stabilize the interface between the electrodes and electrolytes. Figure 3b demonstrates the striking feature of our concentration gradient core-shell structure cathode material that the cycle performance of the CGCS material in the voltage of 3.0-4.3 V at 0.5 C much improved in contrast with both the NCA and NCM materials (Figure S4). After 200 cycles, the CGCS material exhibits outstanding capacity retention of 99.8%, greatly higher than that of NCA (59.3%) and NCM (64.7%). In order to further validate the cycle stability of the material, the cells were performed at a wider voltage range between 3.0 and 4.5 V (Figure 3c). The discharge capacity of the NCA (200 mA h g-1) dramatically decreased to 140 mA h g-1 after 100 cycles, 9 ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 26

whereas the CGCS material exhibits a much more stable cycling life (150 mA h g-1). This result indicates that the concentration-gradient buffer could improve the cycling properties even at high charge voltage 4.5 V. On one hand, the Ni content gradually reduces from the core to the outer layer, so restraining the formation of adverse NiO. On the other hand, stabilized tetravalent Mn enriched on the outer layer acts as a stabilized layer to reduce some side reactions with electrolytes and provides stability that avails long cycle life and safety during the cycling.

19, 38, 47-48

Thus, the

remarkable cycle stability of the CGCS material attributed to well-organized concentration-gradient buffer.

Furthermore, rate performance of the CGCS is improved compared with NCA, especially at high rate of 5 C (Figure 3d). When discharged at the current density of 5 C, CGCS material delivers higher reversible capacity (100 mA h g-1) than NCA (50 mA h g−1). In summary, the CGCS material of the inner end (LiNi0.8Co0.15Al0.05O2) to the outer end (LiNi1/3Co1/3Mn1/3O2) with concentration gradient core-shell structure has a longer cycle life and better rate performance compared with NCA and NCM material. Therefore, CGCS material might be a promising cathode material applied in lithium-ion batteries in the future.

Apart from the superior electrochemical properties, the CGCS material also shows impressive storage stability. Figure 4 shows the cycling performances of CGCS and NCA cathode material after being exposed to a humidity air (30%) for several days at 25 °C. From Figure 4a, it evinced that NCA showed obvious capacity fading (83.7% 10 ACS Paragon Plus Environment

Page 11 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


after 100 cycles) after three days’ air exposure, indicating poor air stability. In contrast, the cycle stability of the CGCS material is almost not affected (98.3% after 100 cycles) (Figure S5). Moreover, CGCS exhibits highly enhanced air stability and can be stored in air for even 15 days without apparent capacity fading (150 mA h g−1 at 0.5 C) as showed in Figure 4b.25, 49-50

To evaluate the thermal stability and safety of the cathode materials, DSC tests were performed. From Figure 5, the onset temperature of the CGCS is approximately 250.5 °C, as the same as NCM, and the main exothermic reaction is observed between 300.2°C and 314.9 °C with the generated heat of 1237 J g-1. In contrast, the onset temperature of the NCA is much lower (191.4 °C), and heat generation is higher (1472 J g-1 at 280.1°C) compared with CGCS. And the generated heat of NCM (1766 J g-1) is higher than that of the CGCS (Table S3), implying the good thermal stability of CGCS.26, 51 As a result, the CGCS material with higher onset temperature and lower heat generation exhibits better thermal performance compared with NCA and NCM cathode material.52-53 We believe that the thermal stability of our concentration gradient core-shell structure is attributed to the slightly lower oxygen release compared with NCA at the elevated temperature.24, 54 It is worth noting that the stable manganese oxide can further improve the thermal stability of the gradient cathode material.55-56 As expected, the stable structure and the Mn4+ in the surface layer play important roles in improving the thermal stability of the CGCS material. Therefore, the thermal stability further highlights the appealing character of the concentration gradient core-shell structure cathode material. 11 ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 26

4. Conclusions

In summary, we have constructed a well-organized concentration gradient core-shell structural cathode material (CGCS) by co-precipitation method, where the inner core of NCA facilitates the high capacity and the concentration-gradient out layer of NCM stabilizes the structure. Consequently, the concentration-gradient buffer demonstrated can effectively protect the surface of NCA microspheres from the side reactions with electrolytes and moisture in air. Thus the CGCS material shows an outstanding cycling stability (99.8% of capacity retention after 200 cycles) and good rate capability (100 mA h g-1 at 5 C) as well as much improved thermal stability. We believe that our concentration gradient core-shell structure cathode material (CGCS) with impressive properties could be one promising high-capacity cathode material for the further application in the lithium-ion batteries. Moreover, our strategy provides new insight into the rational structure design for high-performance cathodes materials.

ASSOCIATED CONTENT

Supporting Information

Supporting Information Available: SEM image and the size distribution of the carbonate precursors, The XRD pattern with Rietveld refinement of CGCS cathode material, XRD patterns of NCA and CGCS material, the electrochemical performances of the NCM material, exact composition analysis of the NCA and CGCS material determined by the inductively coupled plasma (ICP), DSC parameters of the NCA, NCM and CGCS material. 12 ACS Paragon Plus Environment

Page 13 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


AUTHOR INFORMATION Corresponding Author * Tel/Fax: (+86)-10-82617069, E-mail: [email protected] (Y.G.G.); [email protected] (Y.X.Y.).

Author Contributions #

J.-L S. and R. Q.: These authors contributed equally.

Notes The authors declare no competing financial interest.

ACKNOWLEDGMENT This work was supported by the National Natural Science Foundation of China (Grant No. 51225204, 21303222, 21127901, and 51303132), the National Key R&D Program of China (Grant No. 2016YFA0202500), the ‘Strategic Priority Research Program’ of the Chinese Academy of Sciences (Grant No. XDA09010100), and CAS.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 26

REFERENCES

(1) Dunn, B.; Kamath, H.; Tarascon, J. M. Electrical Energy Storage for the Grid: A Battery of Choices. Science 2011, 334, 928-935. (2) Etacheri, V.; Marom, R.; Elazari, R.; Salitra, G.; Aurbach, D. Challenges in the Development of Advanced Li-Ion Batteries: A Review. Energy Environ. Sci. 2011, 4, 3243-3262. (3) Nitta, N.; Wu, F.; Lee, J. T.; Yushin, G. Li-Ion Battery Materials: Present and Future. Mater. Today 2015, 18, 252-264. (4) Goodenough, J. B.; Park, K. S. The Li-Ion Rechargeable Battery: A Perspective. J. Am. Chem. Soc. 2013, 135, 1167-1176. (5) Xia, H.; Xia, Q. Y.; Lin, B. H.; Zhu, J. W.; Seo, J. K.; Meng, Y. S. Self-Standing Porous LiMn2O4 Nanowall Arrays as Promising Cathodes for Advanced 3D Microbatteries and Flexible Lithium-Ion Batteries. Nano Energy 2016, 22, 475-482. (6) Casas-Cabanas, M.; Kim, C.; Rodriguez-Carvajal, J.; Cabana, J. Atomic Defects During Ordering Transitions in LiNi0.5Mn1.5O4 and their Relationship with Electrochemical Properties. J. Mater. Chem. A 2016, 4, 8255-8262. (7) Laszczynski, N.; Birrozzi, A.; Maranski, K.; Copley, M.; Schuster, M. E.; Passerini, S. Effect of Coatings on the Green Electrode Processing and Cycling Behaviour of LiCoPO4. J. Mater. Chem. A 2016, 4, 17121-17128. (8) Thackeray, M. M.; Kang, S.-H.; Johnson, C. S.; Vaughey, J. T.; Benedek, R.; Hackney, S. A. Li2MnO3-Stabilized LiMO2 (M = Mn, Ni, Co) Electrodes for Lithium-Ion Batteries. J. Mater. Chem. 2007, 17, 3112-3125. (9) Gao, X. W.; Deng, Y. F.; Wexler, D.; Chen, G. H.; Chou, S. L.; Liu, H. K.; Shi, Z. C.; Wang, J. Z.


Page 15 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Improving the Electrochemical Performance of the LiNi0.5Mn1.5O4 Spinel by Polypyrrole Coating as a Cathode Material for the Lithium-Ion Battery. J. Mater. Chem. A 2015, 3, 404-411. (10) Liu, W.; Oh, P.; Liu, X.; Lee, M. J.; Cho, W.; Chae, S.; Kim, Y.; Cho, J. Nickel-Rich Layered Lithium Transition-Metal Oxide for High-Energy Lithium-Ion Batteries. Angew. Chem. Int. Ed. 2015, 54, 4440-4457. (11) Guo, Y.-G.; Hu, J.-S.; Wan, L.-J. Nanostructured Materials for Electrochemical Energy Conversion and Storage Devices. Adv. Mater. 2008, 20, 2878-2887. (12) Gao, M. R.; Xu, Y. F.; Jiang, J.; Yu, S. H. Nanostructured Metal Chalcogenides: Synthesis, Modification, and Applications in Energy Conversion and Storage Devices. Chem. Soc. Rev. 2013, 42, 2986-3017. (13) Ellis, B. L.; Lee, K. T.; Nazar, L. F. Positive Electrode Materials for Li-Ion and Li-Batteries. Chem. Mater. 2010, 22, 691-714. (14) Tian, J.; Su, Y.; Wu, F.; Xu, S.; Chen, F.; Chen, R.; Li, Q.; Li, J.; Sun, F.; Chen, S. High-Rate and Cycling-Stable Nickel-Rich Cathode Materials with Enhanced Li+ Diffusion Pathway. ACS Appl. Mater. Interfaces 2016, 8, 582-587. (15) Kim, Y.; Kim, D. Synthesis of High-Density Nickel Cobalt Aluminum Hydroxide by Continuous Coprecipitation Method. ACS Appl. Mater. Interfaces 2012, 4, 586-589. (16) Ma, J.; Hu, P.; Cui, G. L.; Chen, L. Q. Surface and Interface Issues in Spinel LiNi0.5Mn1.5O4: Insights into a Potential Cathode Material for High Energy Density Lithium Ion Batteries. Chem. Mater. 2016, 28, 3578-3606. (17) Shi, J.-L.; Zhang, J.-N.; He, M.; Zhang, X.-D.; Yin, Y.-X.; Li, H.; Guo, Y.-G.; Gu, L.; Wan, L.-J. Mitigating Voltage Decay of Li-Rich Cathode Material via Increasing Ni Content for Lithium-Ion



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 26

Batteries. ACS Appl. Mater. Interfaces 2016, 8, 20138-20146. (18) Zhu, C.; Yu, Y.; Gu, L.; Weichert, K.; Maier, J. Electrospinning of Highly Electroactive Carbon-Coated Single-Crystalline LiFePO4 Nanowires. Angew. Chem., Int. Ed. 2011, 50, 6278-6282. (19) Lim, B.-B.; Yoon, S.-J.; Park, K.-J.; Yoon, C. S.; Kim, S.-J.; Lee, J. J.; Sun, Y.-K. Advanced Concentration Gradient Cathode Material with Two-Slope for High-Energy and Safe Lithium Batteries. Adv. Funct. Mater. 2015, 25, 4673-4680. (20)

Kostecki,

R.;

McLarnon,

F.

Local-Probe

Studies

of

Degradation

of

Composite

LiNi0.8Co0.15Al0.05O2 Cathodes in High-Power Lithium-Ion Cells. Electrochem. Solid-State Lett. 2004, 7, A380-A383. (21) Yao Y.; Liu H.; Li G.; Peng H.; Chen K. Synthesis and Electrochemical Performance of Phosphate-Coated Porous LiNi1/3Co1/3Mn1/3O2 Cathode Material for Lithium Ion Batteries, Electrochimica Acta. 2013, 113, 340–345. (22) Li W.; Song B.; Manthiram, A. High-Voltage Positive Electrode Materials for Lithium-Ion Batteries, Chem. Soc. Rev., 2017, 46, 3006–3059. (23) Zhu L; Liu Y; Wu W; Wu X; Tang W; Wu P. Surface Fluorinated LiNi0.8Co0.15Al0.05O2 as a Positive Electrode Material for Lithium Ion Batteries, J. Mater. Chem. A, 2015, 3, 15156-15162. (24) Kleiner, K.; Dixon, D.; Jakes, P.; Melke, J.; Yavuz, M.; Roth, C.; Nikolowski, K.; Liebau, V.; Ehrenberg, H. Fatigue of LiNi0.8Co0.15Al0.05O2 in Commercial Li Ion Batteries. J. Power Sources 2015, 273, 70-82. (25) Oh, P.; Song, B. H.; Li, W. D.; Manthiram, A. Overcoming the Chemical Instability on Exposure to Air of Ni-Rich Layered Oxide Cathodes by Coating with Spinel LiMn1.9Al0.1O4. J. Mater. Chem. A 2016, 4, 5839-5841.


Page 17 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(26) Belharouak, I.; Lu, W.; Liu, J.; Vissers, D.; Amine, K. Thermal Behavior of Delithiated Li(Ni0.8Co0.15Al0.05)O2 and Li1.1(Ni1/3Co1/3Mn1/3)0.9O2 Powders. J. Power Sources 2007, 174, 905-909. (27) Karki, K.; Huang, Y. Q.; Hwang, S.; Gamalski, A. D.; Whittingham, M. S.; Zhou, G. W.; Stach, E. A. Tuning the Activity of Oxygen in LiNi0.8Co0.15Al0.05O2 Battery Electrodes. ACS Appl. Mater. Interfaces 2016, 8, 27762-27771. (28) Abraham, D. P.; Twesten, R. D.; Balasubramanian, M.; Petrov, I.; McBreen, J.; Amine, K. Surface Changes on LiNi0.8Co0.2O2 Particles during Testing of High-Power Lithium-Ion Cells. Electrochem. Commun. 2002, 4, 620-625. (29) Lee, M. H.; Kang, Y. J.; Myung, S. T.; Sun, Y. K. Synthetic Optimization of Li[Ni1/3Co1/3Mn1/3]O2 via Co-Precipitation. Electrochim. Acta 2004, 50, 939-948. (30) Wang, J. G.; Jin, D. D.; Liu, H. Y.; Zhang, C. B.; Zhou, R.; Shen, C.; Xie, K. Y.; Wei, B. Q. All-Manganese-Based Li-Ion Batteries with High Rate Capability and Ultralong Cycle Life. Nano Energy 2016, 22, 524-532. (31) Li, Y.; Xu, R.; Ren, Y.; Lu, J.; Wu, H. M.; Wang, L. F.; Miller, D. J.; Sun, Y. K.; Amine, K.; Chen, Z. H. Synthesis of Full Concentration Gradient, Cathode Studied by High Energy X-Ray Diffraction. Nano Energy 2016, 19, 522-531. (32) Sun, Y. K.; Chen, Z. H.; Noh, H. J.; Lee, D. J.; Jung, H. G.; Ren, Y.; Wang, S.; Yoon, C. S.; Myung, S. T.; Amine, K. Nanostructured High-Energy Cathode Materials for Advanced Lithium Batteries. Nat. Mater. 2012, 11, 942-947. (33) Lee, K.-S.; Myung, S.-T.; Sun, Y.-K. Synthesis and Electrochemical Performances of Core-Shell Structured Li[(Ni1/3Co1/3Mn1/3)0.8(Ni1/2Mn1/2)0.2]O2 Cathode Material for Lithium Ion Batteries. J. Power Sources 2010, 195, 6043-6048.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 26

(34) Sun, Y.-K.; Myung, S.-T.; Park, B.-C.; Prakash, J.; Belharouak, I.; Amine, K. High-Energy Cathode Material for Long-Life and Safe Lithium Batteries. Nat. Mater. 2009, 8, 320-324. (35) Cho, S.-W.; Kim, G.-O.; Ju, J.-H.; Oh, J.-W.; Ryu, K.-S. X-Ray Absorption Spectroscopy Studies of the Ni Ion of Li(Ni0.8Co0.15Al0.05)0.8(Ni0.5Mn0.5)0.2O2 with a Core–Shell Structure and LiNi0.8Co0.15Al0.05O2 as Cathode Materials. Mater. Res. Bull. 2012, 47, 2830-2833. (36) Li, P.; Ma, R.; Lin, X.; Shao, L.; Wu, K.; Shui, M.; Long, N.; Shu, J. Impact of H2O Exposure on the Structure and Electrochemical Performance of LiVPO4F Cathode Material. J. Alloys Compd. 2015, 637, 20-29. (37) Luo, D.; Fang, S. H.; Tian, Q. H.; Qu, L.; Yang, L.; Hirano, S. I. Discovery of a Surface Protective Layer: A New Insight into Countering Capacity and Voltage Degradation for High-Energy Lithium-Ion Batteries. Nano Energy 2016, 21, 198-208. (38) Wang, Z. J.; Li, B.; Ge, X. M.; Goh, F. W. T.; Zhang, X.; Du, G. J.; Wuu, D.; Liu, Z. L.; Hor, T. S. A.; Zhang, H.; Zong, Y. Co@Co3O4@PPD Core@bishell Nanoparticle-Based Composite as an Efficient Electrocatalyst for Oxygen Reduction Reaction. Small 2016, 12, 2580-2587. (39) Majumder, S. B.; Nieto, S.; Katiyar, R. S. Synthesis and Electrochemical Properties of LiNi0.80(Co0.20−xAlx)O2 (X = 0.0 and 0.05) Cathodes for Li Ion Rechargeable Batteries. J. Power Sources 2006, 154, 262-267. (40) Noh, H.-J.; Chen, Z.; Yoon, C. S.; Lu, J.; Amine, K.; Sun, Y.-K. Cathode Material with Nanorod Structure−An Application for Advanced High-Energy and Safe Lithium Batteries. Chem. Mater. 2013, 25, 2109-2115. (41) Sun, Y.-K.; Myung, S.-T.; Kim, M.-H.; Prakash, J.; Amine, K. Synthesis and Characterization of Li[(Ni0.8Co0.1Mn0.1)0.8(Ni0.5Mn0.5)0.2]O2 with the Microscale Core−Shell Structure as the Positive


Page 19 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Electrode Material for Lthium Batteries. J. Am. Chem. Soc. 2005, 127, 13411-13418. (42) Yoo, G. W.; Jang, B. C.; Son, J. T. Novel Design of Core Shell Structure by NCA Modification on NCM Cathode Material to Enhance Capacity and Cycle Life for Lithium Secondary Battery. Ceram. Int. 2015, 41, 1913-1916. (43) Robert, R.; Bünzli, C.; Berg, E. J.; Novák, P. Activation Mechanism of LiNi0.80Co0.15Al0.05O2: Surface and Bulk Operando Electrochemical, Differential Electrochemical Mass Spectrometry, and X-Ray Diffraction Analyses. Chem. Mater. 2015, 27, 526-536. (44) Zheng, J.; Zhou, W.; Ma, Y.; Jin, H.; Guo, L. Combustion Synthesis of LiNi1/3Co1/3Mn1/3O2 Powders with Enhanced Electrochemical Performance in LIBs. J. Alloys Compd. 2015, 635, 207-212. (45) Makimura, Y.; Sasaki, T.; Nonaka, T.; Nishimura, Y. F.; Uyama, T.; Okuda, C.; Itou, Y.; Takeuchi, Y. Factors Affecting Cycling Life of LiNi0.8Co0.15Al0.05O2 for Lithium-Ion Batteries. J. Mater. Chem. A 2016, 4, 8350-8358. (46) Cho, Y.; Oh, P.; Cho, J. A New Type of Protective Surface Layer for High-Capacity Ni-Based Cathode Materials: Nanoscaled Surface Pillaring Layer. Nano Lett. 2013, 13, 1145-1152. (47) Sun, Y.-K.; Myung, S.-T.; Park, B.-C.; Prakash, J.; Belharouak, I.; Amine, K. High-Energy Cathode Material for Long-Life and Safe Lithium Batteries. Nat. Mater 2009, 8, 320-324. (48) Huang, B.; Li, X.; Wang, Z.; Guo, H.; Shen, L.; Wang, J. A Comprehensive Study on Electrochemical Performance of Mn-Surface-Modified LiNi0.8Co0.15Al0.05O2 Synthesized by an in Situ Oxidizing-Coating Method. J. Power Sources 2014, 252, 200-207. (49) Liu, W.; Hu, G.; Du, K.; Peng, Z.; Cao, Y. Enhanced Storage Property of LiNi0.8Co0.15Al0.05O2 Coated with LiCoO2. J. Power Sources 2013, 230, 201-206. (50) Mijung, N.; Lee, Y.; Cho, J. Water Adsorption and Storage Characteristics of Optimized LiCoO2



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 26

and LiNi1⁄3Co1⁄3Mn1⁄3O2 Composite Cathode Material for Li-Ion Cells. J. Electrochem. Soc. 2006, 153, A935-A940. (51) Nam, K. W.; Bak, S. M.; Hu, E. Y.; Yu, X. Q.; Zhou, Y. N.; Wang, X. J.; Wu, L. J.; Zhu, Y. M.; Chung, K. Y.; Yang, X. Q. Combining in Situ Synchrotron X-Ray Diffraction and Absorption Techniques with Transmission Electron Microscopy to Study the Origin of Thermal Instability in Overcharged Cathode Materials for Lithium-Ion Batteries. Adv. Funct. Mater. 2013, 23, 1047-1063. (52) Wang, Y.; Jiang, J.; Dahn, J. R. The Reactivity of Delithiated Li(Ni1/3Co1/3Mn1/3)O2, Li(Ni0.8Co0.15Al0.05)O2 or LiCoO2 with Non-Aqueous Electrolyte. Electrochem. Commun. 2007, 9, 2534-2540. (53) Belharouak, I.; Lu, W.; Vissers, D.; Amine, K. Safety Characteristics of Li(Ni0.8Co0.15Al0.05)O2 and Li(Ni1/3Co1/3Mn1/3)O2. Electrochem. Commun. 2006, 8, 329-335. (54) Guilmard, M.; Croguennec, L.; Delmas, C. Thermal Stability of Lithium Nickel Oxide Derivatives. Part II: LixNi0.70Co0.15Al0.15O2 and LixNi0.90Mn0.10O2 (X = 0.50 and 0.30). Comparison with LixNi1.02O2 and LixNi0.89Al0.16O2. Chem. Mater. 2003, 15, 4484-4493. (55) Shi, H.; Wang, X.; Hou, P.; Zhou, E.; Guo, J.; Zhang, J.; Wang, D.; Guo, F.; Song, D.; Shi, X.; Zhang, L. Core–Shell Structured Li[(Ni0.8Co0.1Mn0.1)0.7(Ni0.45Co0.1Mn0.45)0.3]O2 Cathode Material for High-Energy Lithium Ion Batteries. J. Alloys Compd. 2014, 587, 710-716. (56) Xiao, J.; Chernova, N. A.; Whittingham, M. S. Influence of Manganese Content on the Performance of LiNi0.9-yMnyCo0.1O2 (0.45 ≤ y ≤ 0.60) as a Cathode Material for Li-Ion Batteries. Chem. Mater. 2010, 22, 1180-1185.


Page 21 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 1. (a) Schematic diagram of the CGCS material. (b) The XRD pattern with Rietveld refinement of CGCS cathode material. (c) SEM image of NCA. (d) SEM image of CGCS.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 26

Figure 2. (a) The cross-sectional image of CGCS and corresponding element maps of Ni, Co, Mn and Al (characterized by EPMA). (b) TEM image CGCS cathode material and the corresponding EDX elemental mappings are shown closely on the right side of TEM image.


Page 23 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 3. (a) The charge-discharge curves of the CGCS material at the current density of 0.1 C and 0.5 C. (b) The cycle stability of the CGCS and NCA material between 3.0 and 4.3 V. (c) The cycle retention of the CGCS and NCA material in the voltage range of 3.0 V-4.5 V. (d) The rate performance of the CGCS and NCA material at different current density, voltage cutoff: 3.0 V-4.3 V.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 26

Figure 4. The cycling performance of the NCA (a) and CGCS (b) materials after the exposure to air with a relative humidity of about 30% for different days. The cell test was conducted between 3.0 and 4.3 V at 25 °C.


Page 25 of 26

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 5. DSC profiles of the delithiated CGCS material, the delithiated NCA material and the NCM material with non-aqueous electrolyte.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 26 of 26


High-Thermal- and Air-Stability Cathode Material with Concentration

Recommend Documents