High-Conductive AZO Nanoparticles Decorated Ni-Rich Cathode

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High-conductive AZO Nanoparticles Decorated Ni-rich Cathode Material with Enhanced Electrochemical Performance Guorong Hu, Manfang Zhang, Lili Wu, Zhongdong Peng, Ke Du, and Yanbing Cao ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.6b08093 • Publication Date (Web): 18 Nov 2016 Downloaded from http://pubs.acs.org on November 20, 2016

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ACS Applied Materials & Interfaces

High-conductive AZO Nanoparticles Decorated Nirich Cathode Material with Enhanced Electrochemical Performance Guorong Hu,† Manfang Zhang, † Lili Wu, † Zhongdong Peng, Ke Du and Yanbing Cao*

School of Metallurgy and Environment, Central South University, Changsha 410083, China. †

These authors contributed equally to this work.

*

Corresponding author. Tel. /fax: +86-073188830474.

E-mail address: [email protected]

Keywords: Cathode material; AZO; Decoration; Rate performance; High-temperature performance.

ACS Paragon Plus Environment

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ABSTRACT A facile solution route was employed for the preparation of Al doped ZnO (AZO) coating layer, which were composed of many AZO nanoparticles. These nanoparticles have an average particle size of 50 nm and have been successfully decorated on the surface of NCM523. As cathode material for lithium ion batteries, the AZO-decorated NCM523 exhibits superior lithium storage improvements according to good cyclic performance, enhanced rate performance (134.2 mAhg-1 after 200 cycles at 10 C) and high-temperature performance (148.9 mAhg-1 at 10 C at 60 °C). Such significant improvement could be attributed to the structural superiority of the AZO decoration out the surface of NCM523, which would stabilize the surface structure of the bulk, suppress the undesirable side reaction at the interface of the electrodes and lead to the enhancement of the conductivity. The preparation of AZO-decorated NCM523 provides an effective method for the high-performance lithium ion batteries and has a certain reference for other materials.


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INTRODUCTION With the ever-growing demands for high performance energy storage systems used in consumer electronics, electric vehicles and large energy storage power station, lithium-ion batteries (LIBs) with high energy density, high power density, low cost and long lifespan are urgently needed.1-4 However, different from the booming capacity of new type anode materials, the specific capacity of cathodes is the real bottleneck for the development of high performance LIBs, which is even lower than the commercialized graphite anode. Recently, vast amount of research have been devoted to developing high energy-density cathode materials by increasing the cutoff voltage.5-7 However, many pure materials suffer from structure disruption and increased surface resistance when these materials are cycled under high cutoff voltage or at high rate, thus causing a fast capacity fading and poor rate performance.8-10 In order to address these problems, surface coating regarded as an effective method has been applied to enhance the surface stability.11-13 Previous works have demonstrated that uniform ZnO film coated cathodes is a proper coating strategy for improving the electrochemical performance of cathodes such as LiCoO2 and LiNi0.5Co0.2Mn0.3O2 materials.14-16 Recently, an inexpensive alternative Al-doped ZnO (AZO) material have been emerged as a promising transparent conductive oxide with a high degree of crystal orientation which would reduce electrical resistivity and increase carrier mobility. Therefore, a coating layer of AZO can be expected to be a reliable method towards enhanced electrochemical performances of NCM523. In this work, a conducting functionalized coating layer of AZO made up of numerous nanoparticles was deposited on the host material through a facile hydrothermal route. The AZO nanoparticles are decorated throughout the NCM523 with an average diameter about 50nm,


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which are formed through a coordination effect or electrostatic attraction between the metal ions (Zn2+, Al3+) and the hydroxyl groups distributed throughout the NCM523. This homogeneous decoration of AZO nanoparticles can not only maintain the electrochemical stability of the host material, but also increase the electronic conduction. As a result, the AZO-decorated NCM523 demonstrates an excellent lithium storage performance with low irreversible capacity loss, superior cycle stability and rate performance.

Experimental Section Preparation of the materials Battery-grade LiNi0.5Co0.2Mn0.3O2 powder was used as the active material of composite electrodes. The preparation process was performed as follows: Firstly, 0.2332 g of Zn(CH3COO)2·2H2O (Xilong Chemical, AR 99.0%), 0.0996 g of Al(NO3)3·9H2O (Aladdin, AR 99.0%) and 10 g of NCM523 powders were added in 50 mL of deionized water respectively, accompanying with ultrasonic treatment. Then, ammonia solution was used for the pH adjustment, and the resulting solution was stirred at 80 °C to remove water. After completion of the reaction, the obtained precursor was subsequently heated at 600 °C for 2 h in air to obtain the required powders. For comparison, the commercial NCM523 was also sintered using the same heat-treatment procedure. Characterization The crystal structures of the powders were confirmed using X-ray powder diffraction (XRD, Rigaku-TTRIII). The X-ray photoelectron spectrometer (XPS) was used for surface element


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analysis. Morphological characterizations of these samples were identified by scanning electron microscopy (SEM, JEOL JSM-6360LV) and high resolution transmission electron microscopy (HRTEM, TECNAI G2 F20). Elemental mappings were recorded through energy dispersive Xray detector (EDX). The thermogravimetric analysis (TGA, SDTQ600) was performed in air at a rate of 5 °C min-1. Electrochemical Characterization The preparation of electrodes and cells were described in detail elsewhere.17-18 The cells were cycled galvanostatically at a constant current density of 0.2 C for the first three cycles and 10 C for the following cycles at 3.0-4.5 V versus Li+/Li on a test instrument (LAND CT-2001A). Differential scanning calorimetry (DSC, SDTQ600) measurements were carried out under Ar atmosphere at a rate of 5 °C min-1. For the preparation of experiments, the coin cells were disassembled after fully charged to 4.5 V at 100th cycle. Then the positive electrodes were removed and peeled off from the aluminum foil. Cyclic voltammetry (CV) and electrochemical impedance spectrometer (EIS) measurements were performed as described in the literature. 19-20

RESULTS AND DISCUSSION Fig. 1a depicts the XRD patterns of both materials. For the as-prepared powders, all diffraction peaks fit well with the reported layered structure of LiNi0.5Co0.2Mn0.3O2.19-20 The patterns show that the pristine NCM523 and AZO-decorated samples exhibit the same hexagonal α-NaFeO2 structure with R-3m space group.21 The (006)/(102) and (108)/(110) peaks show clear splitting, suggesting that the AZO-decorated sample has good crystallinity and well-ordered layered structure.22 The lattice parameters (Table S1) of both samples appear slight change. The


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integrated intensity ratios of I(003)/I(104) obtained from XRD pattern are 1.29 and 1.37 for the pristine NCM523 and AZO-decorated samples, respectively, which implies no obvious cation disorder of both samples and that lower cation mixing appears in the modified sample.13, 23-24 The XRD result demonstrates that the modification does not change the host structure but stabilize the integrated bulk. To investigate the oxidation state of component elements in samples, the corresponding XPS spectra are displayed in Fig. 1b-f. For AZO-decorated NCM523, the binding energy at 854.99 eV of Ni2p3/2 (Fig. 1d) are very close to that for the pristine NCM523 sample (855.09 eV) with the increased intensity, which demonstrates that the oxidation state of Ni in both samples is a mixture of +2 and +3, and AZO decoration does not change the valence state of Ni element in host materials.25-26 Moreover, the binding energy of Co2p3/2 (Fig. 1e) main peaks around 780.09 eV represents the oxidation state of Co is +3, which is in good agreement with the valence of Co in the host composite.19, 27 In addition, the Mn2p3/2 main peaks (Fig. 1f) appear at 642.79 eV of the modified sample and at 642.59 eV of the pristine NCM523 sample corresponding to previous results for LiNi0.5Co0.2Mn0.3O2.18 Meanwhile, the Zn 2p3/2 peak of the AZO-decorated sample shown in Fig. 1b is located at 1021.89 eV, in accordance with Zn2+ oxidation state of the ZnO material.16,

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The spectrum of Al 2s (Fig. 1c) is observed at 118.29 eV, showing that the

predominant oxidation state is +3.29-31 Considering that the signal of matrix elements can be detected after AZO modification, perhaps the AZO nanoparticles are not uniformly coated on the surface of the pristine NCM523 particles. In actually, the existence of AZO are sparsely decorated on the surface and could decrease charge-transfer resistance, which will be discussed in the following the TEM measurement, rate property and EIS analysis.


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From SEM images (Fig. 2), both samples exhibit spherical agglomerates with diameters from 10 to 12 µm which are composed of a lot of 0.5-1.0 µm primary particles. The SEM images of the AZO-decorated material are shown in Fig. 2c and d. Many nanoparticles are distributed on the surface of the bulk (see Fig. 2c) while the surface of the pristine NCM523 in Fig. 2a is relatively smooth and clean. This indicates many AZO nanoparticles adhering to LiNi0.5Co0.2Mn0.3O2 surface with a small degree of agglomeration. Fig. 3 shows the element distributions on the surface of the AZO-decorated material. It can be observed that Al and Zn are concentrated and distributed on the surface of the spherical particles, revealing the existence of the electronic conductive AZO nanoparticles in as-obtained composite. Ni, Co and Mn atoms are distributed uniformly and closely throughout the whole surface, while Al and Zn are concentrated sparsely in the same area, which corresponds to the SEM analysis above, implying the active material LiNi0.5Co0.2Mn0.3O2 is decorated with AZO during preparation of the composite. Fig. 4 shows the TEM images of bare NCM523 and the AZO-decorated NCM523 material. The surface of the pristine NCM523 (Fig. 4a) seems smooth, while many nearly spherical nanoparticles are attached on the surface of the host material as displayed in Fig. 4b. The decoration nanoparticles have an average particle size around 50 nm. The HRTEM image of the decorated sample is shown in Fig. 4c. The crystal lattice fringes of 0.19 nm can be indexed to the (102) planes of the ZnO crystal. The growth mechanism for the decoration of AZO nanoparticles is schematically illustrated in Fig. 4d, which can be ascribed to the electrostatic attraction on the surface of NCM523. During the hydrothermal reaction, the metal ions (Zn2+, Al3+) would be gathered on the surface of the NCM523, attracted by the electrostatic charges from the hydroxyl groups (-OH) throughout the host material. These metal ions agglomerate together to form larger


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clusters and then calcined in air to obtain AZO-decorated NCM523. We believe this conductive AZO decoration would be helpful in obtaining enhanced cycling stability at high rate. Fig. 5a shows the initial discharge/charge profiles of both electrodes at 0.2 C (C=180 mAhg-1). The charge/discharge capacities of the pristine NCM523 at 1st cycles are 213.5/188.6 mAhg-1 while the 1st charge/discharge capacities of the AZO-decorated composite are 208.9/183.4 mAhg-1. The first discharge profile of the modified sample does not show any obvious difference from the bare one. The cycling performance of the electrodes was evaluated at 10 C as displayed in Fig. 5b. The bare NCM523 exhibits poor electrochemical performance after 200th cycles. The specific capacity of the commercial NCM523 cathode decreases quickly to 92.8 mA h g-1, and the corresponding capacity retention is 57.8% of the 1st cycle discharge capacity. For the AZOdecorated, after 200 cycles, the discharge capacity could still maintain at 134.2 mA h g-1, 90.2% of the 1st discharge capacity. The enhancements in the rate performance and the cycle stability of AZO-decorated material can be ascribed to its unique structural characteristic. Firstly, the decoration nanoparticles could act as a buffer for electrolyte decomposition during cycling, further stabilizing the structure of host material. Secondly, the nanoparticles supply the conducting channel for the migration of Li ions and electron (effectively decreasing the charge transfer resistance, which can be proved in Fig. 6c and d). The rate performances of both electrodes are displayed in Fig. S2. The AZO-decorated electrode shows improved rate capability compared with the pristine NCM523. In particular, the AZO-decorated electrode delivers a capacity of 151.1 mA h g-1 at 10 C, superior to the bare one (142.3 mA h g-1). The AZO decoration would be helpful for facile electronic diffusion, which could enhance the rate performance of the host material.


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In order to investigate the enhanced electrochemical performance of AZO-decorated sample, the morphologies of both electrodes after 100 cycles at 10 C have been compared in Fig. S3. The pristine NCM523 sample suffers from severe structure damage with cracked particles, which may result in a rapid capacity fading, while the AZO-decorated sample still remains spherical particle. This result suggests that the highly-conductive AZO decoration nanoparticles could effectively reduce the direct contact between the host material and electrolyte, thus protecting the cathodes from the HF attack, and resulting in the enhanced cycle stability and rate capability. Fig. S4 shows the DSC curves of both electrodes charged to 4.5 V. The exothermic peak of the pristine NCM523 is located at 272.6 °C with a reaction heat of 690.3 J g-1 while the exothermic peak of AZO-decorated NCM523 is shifted to 284.6 °C with a decreased heat generation of 399.0 J g-1. Obviously, the heat generations are remarkably decreased after AZO decoration. This result implies that the AZO decoration could reduce direct contact between the electrolyte solution and the highly unstable oxidized NCM523 materials, thereby remaining excellent structure stability. To further investigate the electrochemical performance of the electrodes at high temperature of 60 °C, the corresponding 1st charge/discharge curve and cycling stability of both electrodes are displayed in Fig. 5c and d, respectively. For the pristine NCM523 sample (Fig. 5c), the initial charge/discharge capacities are 237.8/200.3 mA h g-1 at 0.2 C rate, respectively. After 100 cycles, the capacity retention of 29.6% at 10 C can be observed in Fig. 5d. For the AZOdecorated NCM523 (Fig. 5c), the initial charge/discharge capacities are 225.5/201.6 mA h g-1 at 0.2 C rates. After 100 cycles, the modified sample delivers discharge capacities of 148.9 mA h g1

with an irreversible capacity of 15.6 mA h g-1 (remained capacity retention of 90.5%) at 10 C

rates. It can be seen that the AZO-decorated NCM523 displays a better rate performance than the


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pure bulk at elevated temperature. The improved cyclic stability of the decorated sample at the high temperature is due to the existence of the outer decoration which could stabilize the surface structure of the bulk and protect the host from the side reaction. As shown in Fig. 5d, the pristine NCM523 exhibits a fast capacity fading especially after 40 cycles, due to the more severe side reactions at the interface of the electrode/electrolyte at high temperature and electrolyte decomposition driven by high oxidation.11 Based on those cycling results, it can be believed that the cycling stability can be successfully enhanced by the construction of special architecture with a stable outer decoration, which can effectively stabilize the interfacial structure of the host material. Fig. 6a-b display the CV curves (current vs. potential) of the electrodes between 2.8-4.5 V to investigate the electrochemical behaviors of the samples during cycling. For pure LiNi0.5Co0.2Mn0.3O2, as displayed in Fig. 6a, during the lithiation process of 1st, 2nd and 3th cycle, three apparent voltage peaks at 3.70, 3.70 and 3.72 V can be observed respectively. In the delithiation processes, the apparent peaks at 3.85, 3.81 and 3.80 V are displayed, with corresponding potential interval of 0.15, 0.11 and 0.08 V which can be attributed to the large polarization of lithium ion diffusion. For the decorated composite (Fig. 6b) during the discharge process, these reduction peaks at 3.71, 3.71 and 3.71 V are observed with subsequently overlapping oxidation peaks (3.79, 3.78 and 3.77 V) while the well-defined ∆E are 0.08, 0.07 and 0.06 V. The low and steady ∆E, low charge peak is probably due to the improved reversible lithium insertion into the crystal structure and reduced polarization. To further evaluate the conductivity of both electrodes, EIS measurements were conducted without any cycle and after 50 cycles at room temperature. Specifically, the curves can be divided into 2 parts: a depressed semicircle and a sloping line. The depressed semicircle is


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related to the interfacial charge transfer resistance (Rct).9, 32-33 The sloping line is related to the Li+ diffusion in the solid electrode (Warburg impedance, W).34 Obviously, the modified sample displays considerably smaller semicircle than the pristine NCM523, meaning that the AZO decoration can provide less charge transfer (Table S2) and facilitate the Li ion diffusion. The surface modification with AZO nanoparticles results in the enhanced conductivity, which could improve the electrochemical performances (especially rate performance).

CONCLUSION In summary, a facile solution route was employed for the preparation of AZO outer layer, which were constructed by large numbers of AZO nanoparticles. These nanoparticles have an average particle size of 50 nm and have been successfully decorated on the surface of polyhedron-edged NCM523 bulk. The AZO-decorated NCM523 exhibits enhanced lithium storage properties according to good cycling stability, excellent rate capability (134.2 mAhg-1 after 200 cycles at 10 C) and high-temperature performance (148.9 mAhg-1 at 10 C). Such significant improvement can be attributed to the structural superiority of the AZO decoration which would stabilize the surface structure of the bulk, promote the Li ion transport, facilitate the charge transfer reaction and lead to the enhancement of the conductivity. The present results demonstrate that the AZO-decorated NCM523 sample is a good candidate for the cathodes of LIBs.

ASSOCIATED CONTENT


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Supporting Information available: TGA curve, Rate capability, SEM images, DSC traces, Crystallographic data, and impedance parameters of the pristine NCM523 and AZO-decorated samples.

AUTHOR INFORMATION Corresponding Author *Yanbing Cao. E-mail address: [email protected] Author Contributions §

Guorong Hu, Manfang Zhang and Lili Wu contributed equally to this work. This manuscript

contains contributions of all authors, and all authors have approved of the final version of the manuscript. Notes The authors declare no competing financial interest.

ACKNOWLEDGMENT This work was supported by the National Nature Science Foundation of China (Grant no. 51602352). The authors acknowledge the helpful testing support from the State Key Laboratory of Powder Metallurgy at Central South University.


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Figure 1. (a) XRD patterns of the pristine NCM523 and AZO-decorated samples; XPS profiles of (b) Zn, (c) Al, (d) Ni, (e) Co and (f) Mn on the surface of both samples.


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Figure 2. SEM images of (a and b) the pristine NCM523 and (c and d) AZO-decorated samples.


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Figure 3. (a) SEM images of the AZO-decorated NCM523 and the corresponding EDS elements mapping profiles of (b) Ni, (c) Co, (d) Mn, (e) Zn and (f) Al on the surface of the AZO-decorated samples.


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Figure 4. TEM images of (a) the pristine NCM523 and (b) AZO-decorated materials with corresponding (c) HRTEM image; (d) the schematic illustration for AZO decoration growth on the surface of NCM523.


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Figure 5. Initial charge/discharge curve and cycle stability of the pristine NCM523 and AZOdecorated samples (a and b) at room temperature (25 °C) and (c and d) at high temperature (60 °C).


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Figure 6. CV plots of (a) the pristine NCM523 and (b) AZO-decorated electrodes; EIS plots of the pristine NCM523 and AZO-decorated electrodes (c) without any cycle, (d) after 50 cycles.


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REFERENCES 1.

Tarascon, J.-M.; Armand, M., Issues and Challenges Facing Rechargeable Lithium

Batteries. Nature 2001, 414 (6861), 359-367. 2.

Choi, N. S.; Chen, Z.; Freunberger, S. A.; Ji, X.; Sun, Y. K.; Amine, K.; Yushin, G.;

Nazar, L. F.; Cho, J.; Bruce, P. G., Challenges Facing Lithium Batteries and Electrical Double‐ Layer Capacitors. Angewandte Chemie International Edition 2012, 51 (40), 9994-10024. 3.

Etacheri, V.; Marom, R.; Elazari, R.; Salitra, G.; Aurbach, D., Challenges in the

Development of Advanced Li-Ion Batteries: A Review. Energy & Environmental Science 2011, 4 (9), 3243-3262. 4.

Kang, K.; Meng, Y. S.; Bréger, J.; Grey, C. P.; Ceder, G., Electrodes with High Power and

High Capacity for Rechargeable Lithium Batteries. Science 2006, 311 (5763), 977-980. 5.

Xiong, X.; Wang, Z.; Guo, H.; Zhang, Q.; Li, X., Enhanced Electrochemical Properties of

Lithium-Reactive V 2 O 5 Coated on the LiNi

0.8

Co 0.1 Mn

0.1

O 2 Cathode Material for Lithium

Ion Batteries at 60° C. Journal of Materials Chemistry A 2013, 1 (4), 1284-1288. 6.

Jo, M.; Noh, M.; Oh, P.; Kim, Y.; Cho, J., A New High Power LiNi0. 81Co0. 1Al0. 09o2

Cathode Material for Lithium‐Ion Batteries. Advanced Energy Materials 2014, 4 (13). 7.

Lee, E.-S.; Huq, A.; Chang, H.-Y.; Manthiram, A., High-Voltage, High-Energy Layered-

Spinel Composite Cathodes with Superior Cycle Life for Lithium-Ion Batteries. Chemistry of Materials 2012, 24 (3), 600-612. 8.

Yang, X.; Wang, X.; Hu, L.; Zou, G.; Su, S.; Bai, Y.; Shu, H.; Wei, Q.; Hu, B.; Ge, L.,

Layered Li [Ni

0.5

Co

0.2

Mn

0.3]

O 2–Li

2

MnO

3

Core–Shell Structured Cathode Material with

Excellent Stability. Journal of Power Sources 2013, 242, 589-596. 9.

Liu, K.; Yang, G.-L.; Dong, Y.; Shi, T.; Chen, L., Enhanced Cycling Stability and Rate


19


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 24

Performance of Li [Ni 0.5 Co 0.2 Mn 0.3] O 2 by CeO 2 Coating at High Cut-Off Voltage. Journal of Power Sources 2015, 281, 370-377. 10. Mn

Wang, Z.; Huang, S.; Chen, B.; Wu, H.; Zhang, Y., Infiltrative Coating of LiNi 0.3

O

2

0.5

Co

0.2

Microspheres with Layer-Structured LiTiO 2: Towards Superior Cycling

Performances for Li-Ion Batteries. Journal of Materials Chemistry A 2014, 2 (47), 19983-19987. 11.

Zhang, H.; Li, B.; Wang, J.; Wu, B.; Fu, T.; Zhao, J., Effects of Li 2 MnO 3 Coating on the

High-Voltage Electrochemical Performance and Stability of Ni-Rich Layer Cathode Materials for Lithium-Ion Batteries. RSC Advances 2016, 6 (27), 22625-22632. 12.

Qin, C.; Cao, J.; Chen, J.; Dai, G.; Wu, T.; Chen, Y.; Tang, Y.; Li, A.; Chen, Y.,

Improvement of Electrochemical Performance of Nickel Rich LiNi

0.6

Co 0.2 Mn 0.2 O 2 Cathode

Active Material by Ultrathin Tio 2 Coating. Dalton Transactions 2016, 45 (23), 9669-9675. 13. 2

Choi, J.-w.; Lee, J.-w., Improved Electrochemical Properties of Li (Ni 0.6 Mn 0.2 Co 0.2) O

by Surface Coating with Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3. Journal of Power Sources 2016, 307, 63-68.

14.

Jung, Y. S.; Cavanagh, A. S.; Dillon, A. C.; Groner, M. D.; George, S. M.; Lee, S.-H.,

Enhanced Stability of LiCoO2 Cathodes in Lithium-Ion Batteries Using Surface Modification by Atomic Layer Deposition. Journal of The Electrochemical Society 2010, 157 (1), A75-A81. 15.

Chang, W.; Choi, J.-W.; Im, J.-C.; Lee, J. K., Effects of ZnO Coating on Electrochemical

Performance and Thermal Stability of LiCoO

2

as Cathode Material for Lithium-Ion Batteries.

Journal of Power Sources 2010, 195 (1), 320-326. 16.

Kong, J.-Z.; Ren, C.; Tai, G.-A.; Zhang, X.; Li, A.-D.; Wu, D.; Li, H.; Zhou, F., Ultrathin

ZnO Coating for Improved Electrochemical Performance of LiNi

0.5

Co

0.2

Mn

0.3

O

2

Cathode

Material. Journal of Power Sources 2014, 266, 433-439. 17.

Hu, G.; Zhang, M.; Liang, L.; Peng, Z.; Du, K.; Cao, Y., Mg–Al–B Co-Substitution LiNi


20

Page 21 of 24

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


0.5

Co

0.2

Mn

0.3

O

2

Cathode Materials with Improved Cycling Performance for Lithium-Ion

Battery under High Cutoff Voltage. Electrochimica Acta 2016, 190, 264-275. 18.

Zhang, M.; Hu, G.; Liang, L.; Peng, Z.; Du, K.; Cao, Y., Improved Cycling Performance

of Li 2 MoO 4-Inlaid LiNi

0.5

Co 0.2 Mn

0.3

O 2 Cathode Materials for Lithium-Ion Battery under

High Cutoff Voltage. Journal of Alloys and Compounds 2016, 673, 237-248. 19.

Wang, J.; Yu, Y.; Li, B.; Fu, T.; Xie, D.; Cai, J.; Zhao, J., Improving the Electrochemical

Properties of LiNi 0.5 Co 0.2 Mn 0.3 O 2 at 4.6 V Cutoff Potential by Surface Coating with Li 2 TiO 3

for Lithium-Ion Batteries. Physical Chemistry Chemical Physics 2015, 17 (47), 32033-32043.

20.

Li, L.; Chen, Z.; Zhang, Q.; Xu, M.; Zhou, X.; Zhu, H.; Zhang, K., A Hydrolysis-

Hydrothermal Route for the Synthesis of Ultrathin LiAlO2-Inlaid LiNi0.5Co0.2Mn0.3O2 as a HighPerformance Cathode Material for Lithium Ion Batteries. Journal of Materials Chemistry A 2015, 3 (2), 894-904. 21.

Wu, F.; Tian, J.; Su, Y.; Guan, Y.; Jin, Y.; Wang, Z.; He, T.; Bao, L.; Chen, S., Lithium-

Active Molybdenum Trioxide Coated LiNi 0.5 Co 0.2 Mn 0.3 O 2 Cathode Material with Enhanced Electrochemical Properties for Lithium-Ion Batteries. Journal of Power Sources 2014, 269, 747754. 22.

Lee, S.-W.; Kim, H.; Kim, M.-S.; Youn, H.-C.; Kang, K.; Cho, B.-W.; Roh, K. C.; Kim,

K.-B., Improved Electrochemical Performance of LiNi

0.6

Co

0.2

Mn

0.2

O

2

Cathode Material

Synthesized by Citric Acid Assisted Sol-Gel Method for Lithium Ion Batteries. Journal of Power Sources 2016, 315, 261-268. 23.

Li, J.; Yao, R.; Cao, C., LiNi1/3Co1/3Mn1/3O2 Nanoplates with {010} Active Planes

Exposing Prepared in Polyol Medium as a High-Performance Cathode for Li-Ion Battery. ACS applied materials & interfaces 2014, 6 (7), 5075-5082.


21


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

24.

Page 22 of 24

Liu, T.; Zhao, S.-X.; Wang, K.-Z.; Gou, L.-L.; Nan, C.-W., Improved Rate Capability and

Cycle Stability of Li [Ni

0.5

Co

0.2

Mn

0.3]

O

2

with Li

2

Mno

3

Coating under High Cut-Off

Voltage. Applied Surface Science 2015, 355, 1222-1228. 25.

Liu, X.-H.; Kou, L.-Q.; Shi, T.; Liu, K.; Chen, L., Excellent High Rate Capability and

High Voltage Cycling Stability of Y 2 O 3-Coated LiNi

0.5

Co

0.2

Mn

0.3

O 2. Journal of Power

Sources 2014, 267, 874-880. 26.

Zhu, H.; Xie, T.; Chen, Z.; Li, L.; Xu, M.; Wang, W.; Lai, Y.; Li, J., The Impact of

Vanadium

Substitution

on

the

Structure

and

Electrochemical

Performance

of

LiNi0.5Co0.2Mn0.3O2. Electrochimica Acta 2014, 135, 77-85. 27.

Lee, Y.-M.; Nam, K.-M.; Hwang, E.-H.; Kwon, Y.-G.; Kang, D.-H.; Kim, S.-S.; Song, S.-

W., Interfacial Origin of Performance Improvement and Fade for 4.6 V LiNi0. 5Co0. 2Mn0. 3O2 Battery Cathodes. The Journal of Physical Chemistry C 2014, 118 (20), 10631-10639. 28.

Mahmood, K.; Swain, B. S.; Jung, H. S., Controlling the Surface Nanostructure of ZnO

and Al-Doped ZnO Thin Films Using Electrostatic Spraying for Their Application in 12% Efficient Perovskite Solar Cells. Nanoscale 2014, 6 (15), 9127-9138. 29.

Mcguire, G. E.; Schweitzer, G. K.; Carlson, T. A., Core Electron Binding Energies in

Some Group Iiia, Vb, and Vib Compounds. Inorganic Chemistry 1973, 12 (10), 2450-2453. 30.

Zhao, C.; Du, J.; Huang, D.; Li, Y.; Chen, J.; Li, W., Microstructure and Strong Optical

Absorption Property of the Ag/Al

2

O

3

Nano-Films. Journal of Alloys and Compounds 2016,

671, 419-423. 31.

Stojadinović, S.; Vasilić, R.; Radić, N.; Tadić, N.; Stefanov, P.; Grbić, B., The Formation

of Tungsten Doped Al 2 O 3/ZnO Coatings on Aluminum by Plasma Electrolytic Oxidation and Their Application in Photocatalysis. Applied Surface Science 2016, 377, 37-43.


22

Page 23 of 24

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


32.

Zhu, X.; Wang, Y.; Shang, K.; He, W.; Ai, X.; Yang, H.; Cao, Y., Improved Rate

Capability of the Conducting Functionalized FTO-Coated Li-[Li0.2Mn0.54Ni0.13Co0.13]O2 Cathode Material for Li-Ion Batteries. Journal of Materials Chemistry A 2015, 3 (33), 17113-17119. 33.

Wang, Q.; Sun, J.; Wang, Q.; Zhang, D.-a.; Xing, L.; Xue, X., Electrochemical

Performance of [Small Alpha]-MoO3-In2O3 Core-Shell Nanorods as Anode Materials for Lithium-Ion Batteries. Journal of Materials Chemistry A 2015, 3 (9), 5083-5091. 34.

Riley, L. A.; Lee, S.-H.; Gedvilias, L.; Dillon, A. C., Optimization of MoO3

Nanoparticles as Negative-Electrode Material in High-Energy Lithium Ion Batteries. Journal of Power Sources 2010, 195 (2), 588-592.


23


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Table of Contents


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High-Conductive AZO Nanoparticles Decorated Ni-Rich Cathode

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