Subscriber access provided by Univ. of Tennessee Libraries
Article
Hollow Carbon Nanospheres with Extremely Small Size as Anode Material in Lithium-ion Batteries with Outstanding Cycling Stability Qiulai Huang, Shiliang Wang, Yan Zhang, Bowen Yu, Lizhen Hou, Geng Su, Songshan Ma, Jin Zou, and Han Huang J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.5b10455 • Publication Date (Web): 27 Jan 2016 Downloaded from http://pubs.acs.org on February 2, 2016
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.
The Journal of Physical Chemistry C 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 18
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
The Journal of Physical Chemistry
Hollow Carbon Nanospheres with Extremely Small Size as Anode Material in Lithium-ion Batteries with Outstanding Cycling Stability Qiulai Huang1, Shiliang Wang1,2,*, Yan Zhang3, Bowen Yu1,2, Lizhen Hou4, Geng Su5,*, Songshan Ma1, Jin Zou2, Han Huang2,* 1
School of Physics and Electronics, Central South University, Changsha 410083, China
2
School of Mechanical and Mining Engineering, The University of Queensland, QLD 4072, Australia
3
School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
4
School of Physics and Information Science, Hunan Normal University, Changsha 410081, China
5
College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha 410075, China
Abstract: Hollow carbon nanospheres (HCNSs) were fabricated by annealing the Cu-C core-shell nanoparticles at 1250 oC in vacuum. The as-obtained HCNSs have ultra-thin shell of 1 - 3 nm in thickness, small size of about 20 nm in diameter, high surface area of 300 m2 g-1, and ultra-small pores below 5 nm within the C shells. The HCNSs exhibit excellent electrochemical performance as anode materials for lithium-ion batteries. A reversible capacity of 400 mAh g-1 and capacity retention of nearly 100% are achieved at the current density of 186 mA g-1 after 100 charging-discharging cycles. The high reversible capacity, improved high-rate capability and outstanding cycling stability could be attributed to their unique structural characteristics including the extremely small diameter, the high surface area and the hollow structure with porous, ultrathin shell.
*
Corresponding author. E-mail:
[email protected],
[email protected],
[email protected] 1
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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 Anode materials play a decisive role in the development and commercialization of the lithium-ion batteries.1-3 Carbon anodes, due to their low cost and excellent stability, have been widely used in lithium-ion batteries (LIB).4-6 Recently, apart from the traditional graphitic carbons and hard carbons,4 large number of new carbon materials with various structures, such as hollow carbon nanospheres/microspheres (HCNSs/HCMSs),7-12 hollow carbon nano-onions (HCNOs),13 carbon nanocages (CNCs),14 porous carbon particles (PCPs),15-17 carbon nanotubes (CNTs),18 carbon nano-onions,19 carbon nanobeads,20 graphenes21 and their composites,22-23 have been widely investigated. At the same time, many other new anode materials, such as the nanostructures of silicon,3 tin,24 and metallic oxides,25-26 also exhibit high potentials as the anode materials of LIB. Among these new materials, the hollow nanostructural materials have attracted intensive attention, because they can effective reduce the capacity loss,10 hinder the agglomeration of the active materials, and provide enough space to tolerate the volume expansion during the cycling process of the anode materials.27-30 Combining the advantages of carbon materials and the hollow nanostructures, hollow carbon nanomaterials are expected to be promising candidates for anode materials. As a result, the fabrication and electrochemical performance of hollow carbon nanomaterials have attracted increasing attention in recent years.6-18 So far, various hollow carbon nanomaterials, 2
ACS Paragon Plus Environment
Page 2 of 18
Page 3 of 18
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
The Journal of Physical Chemistry
such as HCNSs/HCMSs, HCNOs, CNCs and PCPs, can be synthesized by many different methods,6-18
and
their
excellent
electrochemical
performance
have
been
widely
investigated.6-18 However, most of the reported hollow carbon nanomaterials have a relatively large particle size of over 100 nm, possibly due to the significant difficulties in the large-scale fabrication of the smaller hollow carbon nanomaterials. Consequently, their corresponding electrochemical performance remains unknown, which needs an attention. In our previous works, we developed a simple method based on one-step metal-organic chemical vapour deposition (MOCVD) for the controlled synthesis of Cu-C core-shell nanostructures with an average size of about 20 nm on a large scale. 31-32 Here, we report that HCNSs of ~ 20 nm in diameter can be easily obtained by simply annealing the Cu-C core-shell nanoparticles at 1250 oC in vacuum, and demonstrate that the as-synthesized HCNSs are a promising candidate as the anode material for LIB with substantially high electrochemical performance.
2. Experimental Section 2.1. Material synthesis and structure characterization HCNSs were prepared by annealing Cu-C core-shell nanoparticles at 1250 oC in vacuum. The Cu-C core-shell nanoparticles were synthesized by MOCVD, and the detailed process can be found in our previous studies.31-34 Briefly, metal-organic precursor Cu(acac)2 was evaporated at 150 oC, and then transported to the deposition region by the H2 carrier gas in a horizontal tube furnace. Cu-C core-shell nanoparticles were collected at the deposition region of the furnace, and their shell thickness and core size could be tuned by changing the deposition temperature and the flow of the carrier gas.31 The obtained Cu-C nanoparticles were then loaded in a corundum boat, and annealed in vacuum at 1250 oC for 10 h in the horizontal tube furnace. After cooled down to room temperature, the annealed produces did not show obvious difference from the previous Cu-C nanoparticle before annealing, but lots 3
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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
of reddish-brown spherical particles with diameter of 1 - 2 mm appeared in the corundum boat. The structural and defective characteristics of the synthesized and annealed products were examined by X-ray diffraction (XRD; Rigaku D max 2500 VB), Raman Spectroscopy (Lab RAMHR 800), transmission electron microscopy (TEM; FEI Tecnai F20 operated at 200 kV). The surface characteristics of the products were characterized by nitrogen adsorption/ desorption isotherms at 77 K on a Quadrasorb SI sorption analyzer. The specific surface areas were calculated according to the Brunauer–Emmett–Teller (BET) model,35 and the pore-size distribution was derived from the density functional theory model.36
2.2. Electrochemical Measurement: Electrochemical tests were carried out in 2016 coin-type cells (diameter: 20 mm; thickness: 1.6 mm). The working electrodes were prepared by coating the slurry of the HNCSs (80 wt%), carbon black (10 wt%) and polyvinylidene fluoride (10 wt%) dissolved in n–methyl pyrrolidinone (NMP) onto a Cu foil substrate, and then dried in a vacuum oven at 100 °C for 12 h. The loading mass of the active material of the electrodes was 0.7 mg cm-2. Li metal foil was utilized as the counter electrode, and Celgard 2400 was used as the separator. The electrolyte was composed of 1 M LiPF6 in ethylene carbonate and dimethyl carbonate (1:1 by volume). Half-cells were assembled in a MBraun glovebox (H2O < 0.5 ppm, O2 < 0.5 ppm) filled with argon. Charge-discharge measurements and cycling tests were performed with an Arbin batteries cycler (BT2000) at room temperature. Cyclic voltammetry measurements were carried out on an electrochemistry workstation (PARSTAT 2273) in the potential range from 0.01 to 3 V versus Li/Li+ at the scan rates of 0.1, 0.2, 0.5 mV/s. The electrochemical impedance measurements were performed on a Solartron Analytical at an AC voltage of 5 mV amplitude in the range from 0.01 to 100 kHz.
4
ACS Paragon Plus Environment
Page 4 of 18
Page 5 of 18
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
The Journal of Physical Chemistry
3. Results and Discussion Figure 1(a) shows the XRD patterns of the products before and after annealing. In addition to the strong ddiffraction peaks from Cu for the sample before annealing, a relatively weak broad shape in the region of C (0002) peak can also be distinguished (see the inset in Figure 1(a)). This indicates that the C shells have a relatively low crystallinity. On the other hand, only an obvious diffraction peak for C (0002) can be detected from the sample after annealing. This suggests that the Cu cores should have been evaporated during the annealing process and the crystallinity of C shells has been improved. To further clarify the effects of the annealing process on the crystallinity of the C shells, the two samples were further characterized by Raman spectroscopy. As can be seen from the Raman spectra in Figure 1(b), two characteristic peaks at around 1337 and 1579 cm−1 can be ascribed to the D band arising from the finite particle-size effect or defects in the hexagonal C network, and the G band from the in-plane bond-stretching motion of pairs of C sp2 atoms.37-40 Although the intensity ratios, ID/IG, for the carbon shells are close, 1.01 (before) and 1.06 (after), the full width at half maximum of G peak increased after annealing. This also suggests that the annealing process improved the crystallinity of C shells, and is consistent with the previous reports.30, 41-42
Figure 1. (a) XRD patterns and (b) Raman spectra of the Cu-C core-shell nanoparticles and the HCNSs. The inset in (a) shows the 8-fold magnification spectrum ranged from 10 to 40 5
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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
degree To understand the change of the structural characteristics during the annealing process, TEM investigations were performed. Figures 2(a) and 2(b) show the TEM images of the Cu-C core-shell nanoparticles before and after annealing, respectively. The insets in Figures 2(a) and 2(b) are the typical high resolution TEM images of the samples, confirming that the annealing process has led to the formation of HCNSs. It should be noted that, in both cases, the C shells have a thickness of ~ 2 nm with the lattice spacing of 0.36 nm. As a direct comparison, Figure 2(c) is the size distributions of the Cu-C core-shell nanoparticles and the HCNSs based on the statistical results summarised from TEM images. It is clear that the HCNSs exhibit a quite similar average size of ~ 20 nm to the Cu-C core-shell nanoparticles, but the size distribution shows some differences. The slight increase in the quantity of the C shells with diameters below 20 nm may be related to the reconstruction and crystallization of the small hollow C shells at the high annealing temperature. The appearance of large shell may be resulted from the break and distortion of the relatively large C shells with diameters above 20 nm.
6
ACS Paragon Plus Environment
Page 6 of 18
Page 7 of 18
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
The Journal of Physical Chemistry
Figure 2. (a,b) TEM images of the Cu-C core-shell nanoparticles and HCNSs, respectively. The insets show the high resolution TEM images of the core-shell particles and HCNSs. (c) Particle-size distribution of the core-shell nanoparticles and HCNSs. (d) Nitrogen adsorption/desorption isotherms and the corresponding pore-size distribution (inset) of the HCNSs. Based on the above-mentioned XRD and TEM analyses, it can be concluded that the annealing process is a simple and effective strategy to remove the Cu cores from Cu-C core-shell nanostructures to ultimately obtain HCNSs. To understand the mechanism of Cu disappearance, i.e., the pathway and driving force, we notice the defective structure of the C shells and the annealing conditions. In our C shells, there were many discontinuities in our C shells, as shown by the arrows in the insets of Figure 2(b). These defects can significantly lower the barrier for the penetration of Cu atoms, and thus provide the pathway for the Cu atoms and atomic clusters to penetrate through the shells. In our experiment, the annealing temperature of 1250 oC is far above the melting point of 1083 oC for bulk Cu, and the actual melting point of the Cu nanocores of ~ 20 nm in diameter is expected to be far below the bulk value due to the considerable melting point depression from the size effects.43-45 The high annealing temperature is therefore able to generate a high Cu vapour pressure in the inner hole of the C shells, establishing a high pressure gradient between the inside and the outside of the shells. This gradient serves as the driving force for the penetration of Cu atoms and atomic 7
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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
clusters through the shell. To understanding the surface characteristics of the Cu-C core-shell nanoparticles before and after annealing, the samples were characterized by the nitrogen absorption/desorption experiment. Using the Brunauer - Emmett - Teller model,35 the specific surface areas were calculated to be 30 and 300 m2 g-1 for the core-shell nanoparticles before and after annealing, respectively. The significant increase of the specific surface area indicates that the evaporation of the Cu cores not only reduced the total mass of the sample, but also led to the hollow structure to increase the surface area, as previously observed by TEM. This also suggests that our HCNSs should be a potential electrode material.46 Figure 2(d) exhibits the nitrogen absorption/desorption isotherm of the obtained HCNSs. The pore distribution curve shown as the inset in Figure 2(d) was derived by the density functional theory (DFT) method. From the pore size distribution curve, a series of pore sizes of 1.4, 1.7, 2.9, 4.3, 7.5, 10.5 and 14.6 nm, can be observed. Compared with the particle-size distribution obtained by direct TEM measurement (Figure 2(c)), it is presumed that the relatively large pores with size above 5 nm should be the inner holes of the C shells. The small pores with size below 5 nm, which is the majority in the pore-size distribution cure but invisible in TEM images, should come from the flaws and defects in the C shells.
8
ACS Paragon Plus Environment
Page 8 of 18
Page 9 of 18
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
The Journal of Physical Chemistry
Figure 3. Electrochemical characteristics of the HCNS electrodes. (a) Galvanostatic charge/discharge curves at 186 mA g-1, (b) CVs of the first four cycles between 3 and 0 V at a scan rate of 0.1 mV s-1, (c) cycling performance at a rate of 186 mA g-1, (d) rate performance at different current rates. The inset in (a) displays the plots of capacity versus cell voltage during the charging process. The inset in (b) shows the CVs at scan rates of 0.1, 0.2 and 0.5 mV/s, respectively. Figure 3 shows the electrochemical characteristics of the HCNS electrodes. Figure 3(a) is the Galvanostatic charge/discharge curves measured at a current rate of 186 mA g-1, from which a large irreversible capacity of 1153 mAh g-1 (0.5C, one Li per six formula units (LiC6) in 2 h) occurs. This is a typical phenomenon for carbonaceous electrodes, due to the formation of solid electrolyte interface (SEI) film.30 The formation of SEI film on the surface of HCNSs is also supported by the plateau at 0.8 - 0.6 V that only occurs in the first charge process.47 The Li storage in the HCNSs electrodes can be further understood by the plots of capacity versus voltage for the first four cycling processes, shown as the inset of Figure 3(a). The two peaks at ~ 0.2 and ~ 1.1 V and a slope from 2.7 to 3.0 V indicate the multiple Li storage positions in the as-obtained HCNSs. The peaks at ~ 0.2 and ~ 1.1 V can be attributed to the Li extraction from C layers and the defects in the HCNSs, respectively.8 The slope from 2.7 to 3.0 V is generally attributed to the surface functional groups (C-H, C-OOH, or C-OH)8, 10, 18 or the surface charge accumulation.48 Since our HCNSs have been annealing at 1250 oC, the 9
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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 18
density of surface functional groups should be very low. It is therefore presumed that the slope may be related to the charge accumulation from the Li absorbed on the surface of the HCNSs.48 Figure 3(b) shows the cyclic voltammograms (CVs) for the first four cycles at a scan rate of 0.1 mV s-1. In the CVs, the cathodic peak at ~ 0.6 V appeared only in the first cycle should be related to the formation of the SEI. The sloping plateau at around 1.0 V in the CV curves has been frequently observed in HCNS-based electrodes,7,
11, 16-17
but the corresponding
mechanism remains unclear. The inset of Figure 3(b) shows the corresponding CVs obtained at different scan speeds of 0.1, 0.2 and 0.5 mV/s. The shapes of these CVs are quite similar, with the same peak positions. This suggests that the HCNSs electrodes should have an excellent reversibility. Figure 3(c) displays the cycling performance of the HCNS electrodes examined under long-term cycling up to 100 cycles. After the low initial values for the first several cycles due to the formation of SEI,8, 16, 30 the coulombic efficiency of our HCNS electrodes exhibits a value of 99%, and holds the value for the subsequent cycles. The first reversible specific capacity of ~ 400 mAh g−1 is achieved at a current density of 186 mA g-1, which is higher than the theoretical value of 372 mAh g-1 for graphite.30 The charge capacity exhibited a slight degradation during the first 52 cycles probably due to the structural instability of the HCNSs in the charging-discharging cycles. After the 52nd cycle, the charge capacity exhibited a slight increase, and then became stable at the 85th cycle. The slight increase in charge capacity after the 52nd cycle can be attributed to the activating process of the pores and cavities in the HCNSs.9, 49 After 100 cycles, the electrodes still maintain a specific reversible capacity of ~ 400 mAh g-1. The excellent cycling stability of the HCNS electrodes can be further verified by its capacities obtained at various charge/discharge current rates, as shown in Figure 3(d). The cell was first cycled at 186 mA g-1 for 5 cycles, followed by cycling with a stepwise 10
ACS Paragon Plus Environment
Page 11 of 18
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
The Journal of Physical Chemistry
increase of discharge/charge current density to as high as 3720 mA g-1. It is shown that the capacity of 390 mAh g–1 is reached again when the current density is lowered back to 186 mA g-1. For comparison, in Table 1 we list the capacity, coulombic efficiency and capacity retention of different electrodes based our HCNS and some other hollow carbon nanostructures. Basically, all these electrodes exhibit relatively high coulombic efficiencies of more than 95% and relatively high capacities. However, the corresponding capacity retentions of these electrodes may vary from ~ 56% to 100%, depending on their structures and the testing conditions. As a remarkable feature, the capacity retention of our HCNS electrode is nearly 100% after 100 cycles, which is significant high than most of other hollow carbon-based electrodes (also see Table 1). It is well-known that the electrochemical performance of an anode material significantly depends on its morphology and structure. So the excellent electrochemical performance of our HCNS electrodes can be understood as follows. Firstly, the high surface area and porous structure can provide a large quantity of accessible active sites for Li-ion insertion and thus may lead to a high reversible specific capacity than the theoretical value for graphite.30 Secondly, the ultrathin shells of 1 ~ 3 nm in thickness and the hollow structure can greatly shorten the diffusion length for Li ions and buffer the volumetric change during the Li-ion insertion and extraction especially at high rates, and consequently lead to the high cycling stability and improved rate capability. Thirdly, our HCNSs have a quite small average diameter of ~ 20 nm, and thus have a higher structural stability than those with relatively large diameters or sheet-like structures, when being subject to the internal stress induced by the Li insertion/extraction and the external stresses originated from van der Waals forces between the neighbouring shells or from the mechanical compression during the fabrication process. As a result, our HCNS electrodes have an excellent cycling stability as shown in Table 1.
Table 1. Electrochemical characteristics of various hollow carbon nanomaterials 11
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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 18
Diameter Coulombic Capacity Loading mass Capacity Cycle Scan rate Materials /thickness efficiency retention Ref. -1 /thickness (m Ah g ) number (mA g-1) (nm) (%) (%) This HCNSs 20 / 2 0.7 mg cm-2 400 99 100 100 186 work HCNSs
100 / 12
1-1.2 mg cm-2
310
100
~ 65
200
372
7
HCNSs
80 /10
-
370
98
~ 80
50
372
8
HCNSs
250 / 5
0.45 mg
760
100
~ 97
100
100
9
HCNSs
380 / 70
400 - 600
98
85 - 90
30
74
10
HCMSs
2000 /
475
100
~ 70
100
100
11
1000
200
100
~ 95
500
200
HCMSs
150/8
743
100
69
50
100
12
HCNOs
30 / 12
391
95
~ 78
60
37
13
PCPs
-
850
93
77
20
100
15
PCPs
-
500
98
~ 56
40
74
16
PCPs
-
250
99
95
100
372
17
365
99
91
100
37
200 - 600
95
60 - 77
50
25
CNTs
-
1.3-2.5 mg cm-2
0.3 mm
18
4. Conclusions In summary, HCNSs with ultra-thin, porous shells of 20 nm in diameter have been prepared on a large scale by simple annealing the Cu-C core-shell nanoparticles at high temperature. The as-obtained HCNSs are demonstrated to be a promising candidate as the Li-ion electrode materials with high reversible capacity, improved high-rate capability and outstanding capacity retention. The superior electrochemical performance of the HCNSs is attributed to their unique structural characteristics that allow improved solid-state Li-ion diffusion and excellent structural stability during the Li inserted-extraction process.
12
ACS Paragon Plus Environment
Page 13 of 18
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
The Journal of Physical Chemistry
Acknowledgements This study is financially supported by the National Natural Science Foundation of China (51074188, 11502080), Research Funding of Central South University (2014JSJJ024) and the Australia Research Council (ARC) under the Discovery Project program (DP130101828).
13
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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
References (1)
Idota, Y. Tin-Based Amorphous Oxide: A High-Capacity Lithium-Ion-Storage Material. Science 1997, 276, 1395-1397.
(2)
Kim, M. G.; Sim, S.; Cho, J. Novel Core-Shell Sn-Cu Anodes for Lithium Rechargeable Batteries Prepared by a Redox-Transmetalation Reaction. Adv. Mater. 2010, 22, 5154-5158.
(3)
Yoo, J. K.; Kim, J.; Jung, Y. S.; Kang, K. Scalable Fabrication of Silicon Nanotubes and Their Application to Energy Storage. Adv. Mater. 2012, 24, 5452-5456.
(4)
Nitta, N.; Wu, F.; Lee, J. T.; Yushin, G. Li-Ion Battery Materials: Present and Future. Materials Today 2015, 18, 252-264.
(5)
Yao, F.; Pham, D. T.; Lee, Y. H. Carbon-Based Materials for Lithium-Ion Batteries, Electrochemical Capacitors, and Their Hybrid Devices. Chemsuschem 2015, 8, 2284-2311.
(6)
Dai, L. M.; Chang, D. W.; Baek, J. B.; Lu, W. Carbon Nanomaterials for Advanced Energy Conversion and Storage. Small 2012, 8, 1130-1166.
(7)
Tang, K.; White, R. J.; Mu, X.; Titirici, M. M.; van Aken, P. A.; Maier, J. Hollow Carbon Nanospheres with a High Rate Capability for Lithium-Based Batteries. ChemSusChem 2012, 5, 400-403.
(8)
Han, F.-D.; Bai, Y.-J.; Liu, R.; Yao, B.; Qi, Y.-X.; Lun, N.; Zhang, J.-X. Template-Free Synthesis of Interconnected Hollow Carbon Nanospheres for High-Performance Anode Material in Lithium-Ion Batteries. Advanced Energy Materials 2011, 1, 798-801.
(9)
Cai, D.; Ding, L.; Wang, S.; Li, Z.; Zhu, M.; Wang, H. Facile Synthesis of Ultrathin-Shell Graphene Hollow Spheres for High-Performance Lithium-Ion Batteries. Electrochim. Acta 2014, 139, 96-103.
(10) Yang, S.; Feng, X.; Zhi, L.; Cao, Q.; Maier, J.; Mullen, K. Nanographene-Constructed Hollow Carbon Spheres and Their Favorable Electroactivity with Respect to Lithium Storage. Adv. Mater. 2010, 22, 838-842. (11) Liu, S.; Mao, C.; Wang, L.; Jia, M.; Sun, Q.; Liu, Y.; Xu, M.; Lu, Z. Bio-Inspired Synthesis of Carbon Hollow Microspheres from Aspergillus Flavus Conidia for Lithium-Ion Batteries. RSC Advances 2015, 5, 59655-59658. 14
ACS Paragon Plus Environment
Page 14 of 18
Page 15 of 18
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
The Journal of Physical Chemistry
(12) Jiang, Z.; Jiang, Z.-J.; Tian, X.; Luo, L. Nitrogen-Doped Graphene Hollow Microspheres as an Efficient Electrode Material for Lithium Ion Batteries. Electrochim. Acta 2014, 146, 455-463. (13) Han, F.-D.; Yao, B.; Bai, Y.-J. Preparation of Carbon Nano-Onions and Their Application as Anode Materials for Rechargeable Lithium-Ion Batteries. The Journal of Physical Chemistry C 2011, 115, 8923-8927. (14) Li, G. D.; Xu, L. Q.; Hao, Q.; Wang, M.; Qian, Y. T. Synthesis, Characterization and Application of Carbon Nanocages as Anode Materials for High-Performance Lithium-Ion Batteries. Rsc Advances 2012, 2, 284-291. (15) Zhou, H.; Zhu, S.; Hibino, M.; Honma, I.; Ichihara, M. Lithium Storage in Ordered Mesoporous Carbon (Cmk-3) with High Reversible Specific Energy Capacity and Good Cycling Performance. Adv. Mater. 2003, 15, 2107-2111. (16) Hu, Y. S.; Adelhelm, P.; Smarsly, B. M.; Hore, S.; Antonietti, M.; Maier, J. Synthesis of Hierarchically Porous Carbon Monoliths with Highly Ordered Microstructure and Their Application in Rechargeable Lithium Batteries with High-Rate Capability. Adv. Funct. Mater. 2007, 17, 1873-1878. (17) Etacheri, V.; Wang, C. W.; O'Connell, M. J.; Chan, C. K.; Pol, V. G. Porous Carbon Sphere Anodes for Enhanced Lithium-Ion Storage. J. Mater. Chem. A 2015, 3, 9861-9868. (18) Wang, X. X.; Wang, J. N.; Chang, H.; Zhang, Y. F. Preparation of Short Carbon Nanotubes and Application as an Electrode Material in Li-Ion Batteries. Adv. Funct. Mater. 2007, 17, 3613-3618. (19) Wang, Q.; Sun, X.; He, D.; Zhang, J. Preparation and Study of Carbon Nano-Onion for Lithium Storage. Mater. Chem. Phys. 2013, 139, 333-337. (20) Wang, H.; Abe, T.; Maruyama, S.; Iriyama, Y.; Ogumi, Z.; Yoshikawa, K. Graphitized Carbon Nanobeads with an Onion Texture as a Lithium-Ion Battery Negative Electrode for High-Rate Use. Adv. Mater. 2005, 17, 2857-2860. (21) Han, S.; Wu, D. Q.; Li, S.; Zhang, F.; Feng, X. L. Porous Graphene Materials for Advanced Electrochemical Energy Storage and Conversion Devices. Adv. Mater. 2014, 26, 849-864. (22) Fan, Z.; Yan, J.; Ning, G.; Wei, T.; Zhi, L.; Wei, F. Porous Graphene Networks as High 15
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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
Performance Anode Materials for Lithium Ion Batteries. Carbon 2013, 60, 558-561. (23) Chen, S.; Yeoh, W.; Liu, Q.; Wang, G. Chemical-Free Synthesis of Graphene–Carbon Nanotube Hybrid Materials for Reversible Lithium Storage in Lithium-Ion Batteries. Carbon 2012, 50, 4557-4565. (24) Wang, G.; Ma, Y. Q.; Liu, Z. Y.; Wu, J. N. Novel Highly Porous Sn–C Composite as High Performance Anode Material for Lithium-Ion Batteries. Electrochim. Acta 2012, 65, 275-279. (25) Luo, J.; Liu, J.; Zeng, Z.; Ng, C. F.; Ma, L.; Zhang, H.; Lin, J.; Shen, Z.; Fan, H. J. Three-Dimensional Graphene Foam Supported Fe3o4 Lithium Battery Anodes with Long Cycle Life and High Rate Capability. Nano Lett. 2013, 13, 6136-6143. (26) Han, H.; Song, T.; Lee, E.-K.; Devadoss, A.; Jeon, Y.; Ha, J.; Chung, Y.-C.; Choi, Y.-M.; Jung, Y.-G.; Paik, U. Dominant Factors Governing the Rate Capability of a Tio2 Nanotube Anode for High Power Lithium Ion Batteries. ACS Nano 2012, 6, 8308-8315. (27) Wang, Z.; Zhou, L.; David Lou, X. W. Metal Oxide Hollow Nanostructures for Lithium-Ion Batteries. Adv. Mater. 2012, 24, 1903-1911. (28) Koo, B.; Xiong, H.; Slater, M. D.; Prakapenka, V. B.; Balasubramanian, M.; Podsiadlo, P.; Johnson, C. S.; Rajh, T.; Shevchenko, E. V. Hollow Iron Oxide Nanoparticles for Application in Lithium Ion Batteries. Nano Lett. 2012, 12, 2429-2435. (29) Yao, Y.; McDowell, M. T.; Ryu, I.; Wu, H.; Liu, N.; Hu, L.; Nix, W. D.; Cui, Y. Interconnected Silicon Hollow Nanospheres for Lithium-Ion Battery Anodes with Long Cycle Life. Nano Lett. 2011, 11, 2949-2954. (30) Kaskhedikar, N. A.; Maier, J. Lithium Storage in Carbon Nanostructures. Adv. Mater.
2009, 21, 2664-2680. (31) Ma, L.; Yu, B.; Wang, S.; Su, G.; Huang, H.; Chen, H.; He, Y.; Zou, J. Controlled Synthesis and Optical Properties of Cu/C Core/Shell Nanoparticles. J. Nanopart. Res.
2014, 16, 2545. (32) Wang, S.; Huang, X.; He, Y.; Huang, H.; Wu, Y.; Hou, L.; Liu, X.; Yang, T.; Zou, J.; Huang, B. Synthesis, Growth Mechanism and Thermal Stability of Copper Nanoparticles Encapsulated by Multi-Layer Graphene. Carbon 2012, 50, 2119-2125. (33) Wang, S.; He, Y.; Liu, X.; Huang, H.; Zou, J.; Song, M.; Huang, B.; Liu, C. T. Novel 16
ACS Paragon Plus Environment
Page 16 of 18
Page 17 of 18
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
The Journal of Physical Chemistry
C/Cu Sheath/Core Nanostructures Synthesized Via Low-Temperature Mocvd. Nanotechnology 2011, 22, 405704. (34) Liu, J., et al. Synthesis and Magnetic Properties of Fe3c-C Core-Shell Nanoparticles. Nanotechnology 2015, 26, 085601. (35) Lehman, J. H.; Terrones, M.; Mansfield, E.; Hurst, K. E.; Meunier, V. Evaluating the Characteristics of Multiwall Carbon Nanotubes. Carbon 2011, 49, 2581-2602. (36) Ustinov, E. A.; Do, D. D.; Fenelonov, V. B. Pore Size Distribution Analysis of Activated Carbons: Application of Density Functional Theory Using Nongraphitized Carbon Black as a Reference System. Carbon 2006, 44, 653-663. (37) Ferrari, A. C.; Robertson, J. Interpretation of Raman Spectra of Disordered and Amorphous Carbon. Phys. Rev. B 2000, 61, 14095 -14107. (38) Yu, B.; Zhang, Q.; Hou, L.; Wang, S.; Song, M.; He, Y.; Huang, H.; Zou, J. Temperature-Dependent Chemical State of the Nickel Catalyst for the Growth of Carbon Nanofibers. Carbon 2016, 96, 904-910. (39) Yu, B.; Wang, S.; Zhang, Q.; He, Y.; Huang, H.; Zou, J. Ni3c-Assisted Growth of Carbon Nanofibres 300 °C by Thermal Cvd. Nanotechnology 2014, 25, 325602. (40) Huang, X.; Hou, L.; Yu, B.; Chen, G.; Wang, S.; Ma, L.; Liu, X.; He, Y. Preparation, Formation Mechanism and Optical Properties of C/Cu Shell/Core Nanostructures. Acta Phys. Sin. 2013, 62, 108102. (41) Han, C. C.; Lee, J. T.; Chang, H. Thermal Annealing Effects on Structure and Morphology of Micrometer-Sized Carbon Tubes. Chem. Mater. 2001, 13, 4180-4186. (42) Ci, L. J.; Wei, B. Q.; Xu, C. L.; Liang, J.; Wu, D. H.; Xie, S. S.; Zhou, W. Y.; Li, Y. B.; Liu, Z. Q.; Tang, D. S. Crystallization Behavior of the Amorphous Carbon Nanotubes Prepared by the Cvd Method. J. Cryst. Growth 2001, 233, 823-828. (43) Bokhonov, B. B.; Novopashin, S. A. In Situ Investigation of Morphological and Phase Changes During Thermal Annealing and Oxidation of Carbon-Encapsulated Copper Nanoparticles. J. Nanopart. Res. 2010, 12, 2771-2777. (44) Schaper, A. K.; Phillipp, F.; Hou, H. Melting Behavior of Copper Nanocrystals Encapsulated in Onion-Like Carbon Cages. J. Mater. Res. 2005, 20, 1844-1850. (45) Schaper, A. K.; Hou, H.; Greiner, A.; Schneider, R.; Phillipp, F. Copper Nanoparticles 17
ACS Paragon Plus Environment
The Journal of Physical Chemistry
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 18
Encapsulated in Multi-Shell Carbon Cages. Appl. Phys. A: Mater. Sci. Process. 2004, 78, 73-77. (46) Peigney, A.; Laurent, C.; Flahaut, E.; Bacsa, R. R.; Rousset, A. Specific Surface Area of Carbon Nanotubes and Bundles of Carbon Nanotubes. Carbon 2001, 39, 507-514. (47) Lahiri, I.; Oh, S.-W.; Hwang, J. Y.; Cho, S.; Sun, Y.-K.; Banerjee, R.; Choi, W. High Capacity
and
Excellent
Stability
of
Lithium
Ion
Battery
Anode
Using
Interface-Controlled Binder-Free Multiwall Carbon Nanotubes Grown on Copper. ACS Nano 2010, 4, 3440-3446. (48) Yang, S. B.; Huo, J. P.; Song, H. H.; Chen, X. H. A Comparative Study of Electrochemical Properties of Two Kinds of Carbon Nanotubes as Anode Materials for Lithium Ion Batteries. Electrochim. Acta 2008, 53, 2238-2244. (49) Qie, L.; Chen, W. M.; Wang, Z. H.; Shao, Q. G.; Li, X.; Yuan, L. X.; Hu, X. L.; Zhang, W. X.; Huang, Y. H. Nitrogen-Doped Porous Carbon Nanofiber Webs as Anodes for Lithium Ion Batteries with a Superhigh Capacity and Rate Capability. Adv. Mater. 2012, 24, 2047-2050.
18
ACS Paragon Plus Environment