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3D architecture constructed by 2D SnS2-graphene hybrids towards large and fast lithium storage
Materials Letters 185 (2016) 311–314
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
3D architecture constructed by 2D SnS2-graphene hybrids towards large and fast lithium storage Qianwen Zhang a, Yanfang Sun b, Xiao Zhang a,n, Jinxue Guo a,n a Key Laboratory of Sensor Analysis of Tumor Marker (Ministry of Education), College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China b College of Science and Technology, Agricultural University of Hebei, Cangzhou 061100, PR China
art ic l e i nf o
a b s t r a c t
Article history: Received 7 June 2016 Received in revised form 1 July 2016 Accepted 31 August 2016 Available online 6 September 2016
3D architecture constructed by 2D hybrids of few-layer SnS2 nanoplates and graphene has been prepared via a facile solvothermal method using tin tetrachloride, thiourea, graphene oxide nanosheets, and sodium dodecyl sulfonate as starting materials. The sample is characterized by SEM, TEM, XRD, and TG techniques, revealing that the few-layer SnS2 nanoplates are well dispersed and tightly contacted onto graphene substrates, and the 2D hybrids assembly into 3D architecture. Endowed with the structural and compositional advantages of the specific architecture, the SnS2-graphene composite exhibits good electrochemical properties as anode for lithium-ion batteries, including high capacity, good cyclic stability (826 mA h g 1 at current density of 0.5 A g 1 after 200 cycles), and excellent high-rate performance (498 mA h g 1 at 8 A g 1). & 2016 Elsevier B.V. All rights reserved.
Keywords: Tin sulfides Graphene Composite materials 3D architecture Energy storage and conversion
1. Introduction Novel anode materials for high-performance lithium-ion batteries (LIBs) have aroused extensive research interests [1]. 2D nanomaterials, possessing shorten path for lithium diffusion and high surface for electrode/electrolyte contact, are on the research focus [2–4]. Particularly, 2D metal sulfides with layered structure have been studied intensively due to the high theoretical capacity and fascinating structure [5–8]. SnS2 is believed as the promising anode material because of its abundance, low cost, and stability [8]. However, its application is hampered by the terrible capacity decay and unsatisfied rate performance, which are associated with the intrinsic volume effect and poor electric conductivity. To mitigate these bottlenecks, graphene has been employed to boost the lithium storage properties of metal sulfides because of its good electrical conductivity and mechanical flexibility [9–12]. Recently, 2D nanosheets fabricated 3D architectures have demonstrated good lithium storage properties due to the additional structural benefits [9]. However, the formation of 3D architecture constructed by 2D hybrids of SnS2 and graphene (SnS2-G) via the solvothermal method has rarely been reported. Herein, we present the 3D architecture assembled by 2D hybrids of few-layer SnS2 nanoplates and graphene via a solvothermal method. Endowed with the structural advantages, the SnS2-G manifests good n
Corresponding authors. E-mail addresses: [email protected] (X. Zhang), [email protected] (J. Guo).
http://dx.doi.org/10.1016/j.matlet.2016.08.153 0167-577X/& 2016 Elsevier B.V. All rights reserved.
electrochemical properties as anode material.
2. Experimental Graphene oxide (GO, 70 mg), SnCl4 5H2O (1.2 mmol), thiourea (2.4 mmol), and sodium dodecyl sulfonate (SDS, 0.2 g) are added into 30 mL mixed deionized water and ethylene glycol (1:1 in volume). The black solution is sealed in 40 mL Teflon-lined autoclave and heated at 180 °C for 20 h in an oven. The resultant cylindrical hydrogels are freeze-dried and then sintered at 400 °C in Ar to obtain the SnS2-G 3D architecture. The SnS2-G is characterized with X-ray powder diffraction (XRD) using a Philips X'-pert X-ray diffractometer with Cu Kα radiation, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) from a JEOL JSM-7500F, and transmission electron micrographs (TEM) analysis on a FEI TECNAI F30. The thermogravimetric (TG) measurement is conducted on PerkinElmer TGA 7 thermal analyzer from room temperature to 800 °C with a heating rate of 10 °C min 1 in air. CR2016-type coin cell is used for electrochemical tests. SnS2-G, acetylene black, and polyvinylidene fluoride (PVDF) in a weight ratio of 8:1:1 are compressed onto a copper foil, which is then vacuum dried at 120 °C as working electrode. Metallic lithium sheet is used as the negative electrode. The Clegard 2300 microporous film is used as separator. The electrolyte is 1 M LiPF6 in a mixture of ethylene carbonate (EC)/dimethyl carbonate (DMC)/ ethyl methyl carbonate (EMC) (1:1:1 in volume). The cell is
312
Q. Zhang et al. / Materials Letters 185 (2016) 311–314
assembled in a glove box filled with pure argon. The electrochemical tests are performed between 3 and 0.01 V on LAND CT2001A Battery Cycler (Wuhan China).
3. Results and discussion Fig. 1 displays possible fabrication process of the 3D architecture. Firstly, SDS molecules act as bridging molecules to adsorb Sn4 þ onto the surface of GO and assure their homogeneous dispersion [13]. With the temperature increasing, thiourea decompose to release H2S, which reacts with Sn4 þ to in-situ form SnS2 crystal nucleus on the graphene surface. These nucleuses then grow up into few-layer nanoplates and couple with graphene to obtain 2D hybrid of SnS2-G. And the 2D hybrids intertwine with each other to construct the 3D SnS2-G architecture [9]. This formation process assures the tight contact and smooth electron exchange between SnS2 and graphene, thus inducing fast electrochemical reaction kinetics. The digital photos show the SnS2-G obtained in 40 mL autoclave, in which the black cylindrical 3D architecture of 40 mm in height and 25 mm in diameter can be seen. The sample (Fig. S1) obtained in 80 mL autoclave shows 50 mm in height and 40 mm in diameter, indicating the present synthesis method could achieve the scalable preparation of SnS2-G cylinder. The SEM image of Fig. 2a shows the formation of hybrid SnS2-G. In the magnified SEM image (Fig. 2b), the SnS2 nanoplates show several hundreds of nanometers in diameter, which are well entrapped in flexible graphene nanosheets. These 2D hybrids are stacked and connected into 3D architecture. Sn, S, C, and O elements can be observed in Fig. 2c. Sn and S are assigned to SnS2. Element C is due to graphene. The trace amount of O should be attributed to the residual oxygen groups of graphene [9]. One can see from Fig. 2b, these elements are well dispersed and overlapped, indicating the good coupling between SnS2 and graphene. In TEM image (Fig. 2e), graphene nanosheets display wrinkled nature, and SnS2 nanoplates show relatively rigid feature. SnS2 nanoplates are well deposited on graphene substrate, and distinctive boundaries can be observed between them. The HRTEM image (Fig. 2f) shows that, SnS2 nanoplates possess typical layered structure with interlayer distance of 0.6 nm, corresponding to (001) plane of 2T SnS2. And about 5–8 layers are determined for SnS2 nanoplates. In the powder XRD pattern (Fig. 3a) of SnS2-G, all diffraction peaks are assigned to 2T type SnS2 with hexagonal phase (JCPDS 23-0677). The intensity of (001) peak is much lower compared with standard XRD pattern of 2T SnS2, suggesting that the crystal growth along c-axis is suppressed for SnS2 nanoplates. It should be assigned to the space confinement effect of graphene in the composite [11]. Based on (001) plane, the average thickness of SnS2 nanoplates can be calculated to be 3.6 nm using the Scherrer equation. The average number is calculated to be 6 layers from the interlayer distance of 0.59 nm, in consistent with the TEM result. The peak of graphene cannot be detected, suggesting that the restack of graphene nanosheet is prevented
[10,11]. This should be attributed to the in-situ nucleate and formation of SnS2 on the graphene surface, which in turn hinders their restacking [11]. TG curve (Fig. 3b) shows three weightlessness regions, which is similar to the previous reports [10,12]. The first region before 250 °C is due to the loss of absorbed water and decomposition of residual oxygen-containing groups of graphene [7,10–12]. The following weight loss can be attributed to the decomposition of graphene and oxidation of SnS2 into SnO2 over 650 °C, respectively [10,12]. Based on the weight loss of 3.5% for water and the total weight loss of 33.2%, the weight fraction of graphene in SnS2-G is 16%. To evaluate the potential application for large and fast lithium storage, the electrochemical tests of SnS2-G are performed at high current densities. Fig. 4a displays the 1st, 2nd, 10th, and 200th cycles of galvanostatic charge-discharge profiles at high rate of 500 mA g 1, and the typical voltage profiles for SnS2 anodes are observed [8,10–12]. The plateau at 1.25 V corresponds to the conversion from Sn4 þ to Sn, and the plateau ranging from 0.5 to 0.01 V could be assigned to the alloying of Li þ with Sn. SnS2-G shows a high initial discharge capacity of 1229 mA h g 1 with corresponding Coulombic efficiency of 73%. The irreversible capacity loss at the first cycle mainly comes from the formation of solid electrolyte interface (SEI). The discharge capacity decreases to 933 mA h g 1 at the second cycle, with a remarkably increased Coulombic efficiency of 92%, indicating the high reversibility. The curves in the 10th and 200th cycles overlap very well, showing the good cyclic stability. The durable cyclic test (Fig. 4b) further confirms this. SnS2-G achieves a very stable cyclic performance over 200 cycles at 500 mA g 1. After 200 cycles, a high discharge capacity of 826 mA h g 1 is retained, showing high capacity retention. The good cyclic stability should be assigned to the 2D feature of the hybrid SnS2-G and the good flexibility of graphene substrates, both of which could effectively buffer the volume changes and thus assuring the good cyclic stability. The rate test (Fig. 4c) is conducted between 0.5 and 8 A g 1. Specific capacities of 854, 780, 728, 625, and 498 mA h g 1 can be obtained at 0.5, 1, 2, 4, and 8 A g 1, respectively, delivering excellent rate capability. The combined advantages are responsible for this, including large surface area of 2D hybrids, graphene with high electrical conductivity, and the 3D architecture for convenient electrolyte infiltration and smooth electron/ion transfer. A high capacity of 796 mA h g 1 can be recovered when the current density decreases back to 0.5 A g 1, revealing high stability and reversibility of SnS2-G.
4. Conclusions In summary, 3D framework composed of 2D hybrid few-layer SnS2 nanoplates and graphene has been prepared via solvothermal process. Such specific 3D architecture possesses combined advantages for electrochemical lithium storage, including (1) 2D hybrids supply high surface area for active materials/electrolyte contact and structural stability to accommodate the volume changes; (2) tight contact between SnS2 and graphene assures the
Fig. 1. Schematic formation of 3D architecture assembled by 2D hybrids of SnS2-G.
Q. Zhang et al. / Materials Letters 185 (2016) 311–314
313
Fig. 2. (a, b) SEM images of SnS2-G. (c) SEM image and (d) the corresponding EDS mapping of Sn, S, C, and O elements. (e, f) TEM images of SnS2-G.
fast electron exchange; (3) flexible graphene could buffer the volume variation of SnS2; (4) 3D architecture facilitates the infiltration of electrolyte and fast the electron and lithium ion diffusion. Therefore, SnS2-G delivers excellent electrochemical lithium storage properties, especially high-capacity and high-rate performance, making it a promising candidate of anode material for high-performance LIBs.
Acknowledgements This work was supported by Shandong Provincial Natural Science Foundation, China (ZR2014JL015, ZR2014EMM004). Appendix A. Supplementary material Supplementary data associated with this article can be found in the online version at http://dx.doi.org/10.1016/j.matlet.2016.08.153.
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Q. Zhang et al. / Materials Letters 185 (2016) 311–314
Fig. 3. (a) XRD pattern and (b) TG analysis of SnS2-G.
Fig. 4. The electrochemical properties of SnS2-G: (a) The 1st, 2nd, 10th, and 100th cycles of galvanostatic charge-discharge profiles and (b) cyclic performance of between 0.01 and 3 V at current density of 500 mA g 1. (c) Rate capability at current densities ranging between 0.5 and 8 A g 1.
References [1] [2] [3] [4] [5]
J.M. Tarascon, M. Armand, Nature 414 (2001) 359. J. Guo, B. Jiang, X. Zhang, L. Tang, Y.H. Wen, J. Mater. Chem. A 3 (2015) 2251. J. Liu, X.W. Liu, Adv. Mater. 24 (2012) 4097. X. Zhang, B. Jiang, J. Guo, Y. Xie, L. Tang, J. Power Sources 268 (2014) 365. R. Lv, J.A. Robinson, R.E. Schaak, D. Sun, Y. Sun, T.E. Mallouk, M. Terrones, Acc. Chem. Res. 48 (2015) 56. [6] Z. Wu, B. Li, Y. Xue, J. Li, Y. Zhang, F.J. Gao, Mater. Chem. A 3 (2015) 19445. [7] J. Guo, F. Li, Y. Sun, X. Zhang, L. Tang, J. Power Sources 291 (2015) 195.
[8] J. Ma, D. Lei, X. Duan, Q. Li, T. Wang, A. Cao, Y. Mao, W. Zheng, RSC Adv. 2 (2012) 3615. [9] X. Zhang, Q. Zhang, Y. Sun, P. Zhang, X. Gao, W. Zhang, Guo, J. Electrochim. Acta 189 (2016) 224. [10] B. Luo, Y. Fang, B. Wang, J. Zhou, H. Song, L. Zhi, Energy Environ. Sci. 5 (2012) 5226. [11] K. Chang, Z. Wang, G. Huang, H. Li, W. Chen, J.Y. Lee, J. Power Sources 201 (2012) 259. [12] Q. Zhang, R. Li, M. Zhang, B. Zhang, X. Gou, Electrochim. Acta 115 (2014) 425. [13] J. Guo, B. Jiang, X. Zhang, H. Liu, J. Power Sources 262 (2014) 15.
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
3D architecture constructed by 2D SnS2-graphene hybrids towards large and fast lithium storage Qianwen Zhang a, Yanfang Sun b, Xiao Zhang a,n, Jinxue Guo a,n a Key Laboratory of Sensor Analysis of Tumor Marker (Ministry of Education), College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China b College of Science and Technology, Agricultural University of Hebei, Cangzhou 061100, PR China
art ic l e i nf o
a b s t r a c t
Article history: Received 7 June 2016 Received in revised form 1 July 2016 Accepted 31 August 2016 Available online 6 September 2016
3D architecture constructed by 2D hybrids of few-layer SnS2 nanoplates and graphene has been prepared via a facile solvothermal method using tin tetrachloride, thiourea, graphene oxide nanosheets, and sodium dodecyl sulfonate as starting materials. The sample is characterized by SEM, TEM, XRD, and TG techniques, revealing that the few-layer SnS2 nanoplates are well dispersed and tightly contacted onto graphene substrates, and the 2D hybrids assembly into 3D architecture. Endowed with the structural and compositional advantages of the specific architecture, the SnS2-graphene composite exhibits good electrochemical properties as anode for lithium-ion batteries, including high capacity, good cyclic stability (826 mA h g 1 at current density of 0.5 A g 1 after 200 cycles), and excellent high-rate performance (498 mA h g 1 at 8 A g 1). & 2016 Elsevier B.V. All rights reserved.
Keywords: Tin sulfides Graphene Composite materials 3D architecture Energy storage and conversion
1. Introduction Novel anode materials for high-performance lithium-ion batteries (LIBs) have aroused extensive research interests [1]. 2D nanomaterials, possessing shorten path for lithium diffusion and high surface for electrode/electrolyte contact, are on the research focus [2–4]. Particularly, 2D metal sulfides with layered structure have been studied intensively due to the high theoretical capacity and fascinating structure [5–8]. SnS2 is believed as the promising anode material because of its abundance, low cost, and stability [8]. However, its application is hampered by the terrible capacity decay and unsatisfied rate performance, which are associated with the intrinsic volume effect and poor electric conductivity. To mitigate these bottlenecks, graphene has been employed to boost the lithium storage properties of metal sulfides because of its good electrical conductivity and mechanical flexibility [9–12]. Recently, 2D nanosheets fabricated 3D architectures have demonstrated good lithium storage properties due to the additional structural benefits [9]. However, the formation of 3D architecture constructed by 2D hybrids of SnS2 and graphene (SnS2-G) via the solvothermal method has rarely been reported. Herein, we present the 3D architecture assembled by 2D hybrids of few-layer SnS2 nanoplates and graphene via a solvothermal method. Endowed with the structural advantages, the SnS2-G manifests good n
Corresponding authors. E-mail addresses: [email protected] (X. Zhang), [email protected] (J. Guo).
http://dx.doi.org/10.1016/j.matlet.2016.08.153 0167-577X/& 2016 Elsevier B.V. All rights reserved.
electrochemical properties as anode material.
2. Experimental Graphene oxide (GO, 70 mg), SnCl4 5H2O (1.2 mmol), thiourea (2.4 mmol), and sodium dodecyl sulfonate (SDS, 0.2 g) are added into 30 mL mixed deionized water and ethylene glycol (1:1 in volume). The black solution is sealed in 40 mL Teflon-lined autoclave and heated at 180 °C for 20 h in an oven. The resultant cylindrical hydrogels are freeze-dried and then sintered at 400 °C in Ar to obtain the SnS2-G 3D architecture. The SnS2-G is characterized with X-ray powder diffraction (XRD) using a Philips X'-pert X-ray diffractometer with Cu Kα radiation, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) from a JEOL JSM-7500F, and transmission electron micrographs (TEM) analysis on a FEI TECNAI F30. The thermogravimetric (TG) measurement is conducted on PerkinElmer TGA 7 thermal analyzer from room temperature to 800 °C with a heating rate of 10 °C min 1 in air. CR2016-type coin cell is used for electrochemical tests. SnS2-G, acetylene black, and polyvinylidene fluoride (PVDF) in a weight ratio of 8:1:1 are compressed onto a copper foil, which is then vacuum dried at 120 °C as working electrode. Metallic lithium sheet is used as the negative electrode. The Clegard 2300 microporous film is used as separator. The electrolyte is 1 M LiPF6 in a mixture of ethylene carbonate (EC)/dimethyl carbonate (DMC)/ ethyl methyl carbonate (EMC) (1:1:1 in volume). The cell is
312
Q. Zhang et al. / Materials Letters 185 (2016) 311–314
assembled in a glove box filled with pure argon. The electrochemical tests are performed between 3 and 0.01 V on LAND CT2001A Battery Cycler (Wuhan China).
3. Results and discussion Fig. 1 displays possible fabrication process of the 3D architecture. Firstly, SDS molecules act as bridging molecules to adsorb Sn4 þ onto the surface of GO and assure their homogeneous dispersion [13]. With the temperature increasing, thiourea decompose to release H2S, which reacts with Sn4 þ to in-situ form SnS2 crystal nucleus on the graphene surface. These nucleuses then grow up into few-layer nanoplates and couple with graphene to obtain 2D hybrid of SnS2-G. And the 2D hybrids intertwine with each other to construct the 3D SnS2-G architecture [9]. This formation process assures the tight contact and smooth electron exchange between SnS2 and graphene, thus inducing fast electrochemical reaction kinetics. The digital photos show the SnS2-G obtained in 40 mL autoclave, in which the black cylindrical 3D architecture of 40 mm in height and 25 mm in diameter can be seen. The sample (Fig. S1) obtained in 80 mL autoclave shows 50 mm in height and 40 mm in diameter, indicating the present synthesis method could achieve the scalable preparation of SnS2-G cylinder. The SEM image of Fig. 2a shows the formation of hybrid SnS2-G. In the magnified SEM image (Fig. 2b), the SnS2 nanoplates show several hundreds of nanometers in diameter, which are well entrapped in flexible graphene nanosheets. These 2D hybrids are stacked and connected into 3D architecture. Sn, S, C, and O elements can be observed in Fig. 2c. Sn and S are assigned to SnS2. Element C is due to graphene. The trace amount of O should be attributed to the residual oxygen groups of graphene [9]. One can see from Fig. 2b, these elements are well dispersed and overlapped, indicating the good coupling between SnS2 and graphene. In TEM image (Fig. 2e), graphene nanosheets display wrinkled nature, and SnS2 nanoplates show relatively rigid feature. SnS2 nanoplates are well deposited on graphene substrate, and distinctive boundaries can be observed between them. The HRTEM image (Fig. 2f) shows that, SnS2 nanoplates possess typical layered structure with interlayer distance of 0.6 nm, corresponding to (001) plane of 2T SnS2. And about 5–8 layers are determined for SnS2 nanoplates. In the powder XRD pattern (Fig. 3a) of SnS2-G, all diffraction peaks are assigned to 2T type SnS2 with hexagonal phase (JCPDS 23-0677). The intensity of (001) peak is much lower compared with standard XRD pattern of 2T SnS2, suggesting that the crystal growth along c-axis is suppressed for SnS2 nanoplates. It should be assigned to the space confinement effect of graphene in the composite [11]. Based on (001) plane, the average thickness of SnS2 nanoplates can be calculated to be 3.6 nm using the Scherrer equation. The average number is calculated to be 6 layers from the interlayer distance of 0.59 nm, in consistent with the TEM result. The peak of graphene cannot be detected, suggesting that the restack of graphene nanosheet is prevented
[10,11]. This should be attributed to the in-situ nucleate and formation of SnS2 on the graphene surface, which in turn hinders their restacking [11]. TG curve (Fig. 3b) shows three weightlessness regions, which is similar to the previous reports [10,12]. The first region before 250 °C is due to the loss of absorbed water and decomposition of residual oxygen-containing groups of graphene [7,10–12]. The following weight loss can be attributed to the decomposition of graphene and oxidation of SnS2 into SnO2 over 650 °C, respectively [10,12]. Based on the weight loss of 3.5% for water and the total weight loss of 33.2%, the weight fraction of graphene in SnS2-G is 16%. To evaluate the potential application for large and fast lithium storage, the electrochemical tests of SnS2-G are performed at high current densities. Fig. 4a displays the 1st, 2nd, 10th, and 200th cycles of galvanostatic charge-discharge profiles at high rate of 500 mA g 1, and the typical voltage profiles for SnS2 anodes are observed [8,10–12]. The plateau at 1.25 V corresponds to the conversion from Sn4 þ to Sn, and the plateau ranging from 0.5 to 0.01 V could be assigned to the alloying of Li þ with Sn. SnS2-G shows a high initial discharge capacity of 1229 mA h g 1 with corresponding Coulombic efficiency of 73%. The irreversible capacity loss at the first cycle mainly comes from the formation of solid electrolyte interface (SEI). The discharge capacity decreases to 933 mA h g 1 at the second cycle, with a remarkably increased Coulombic efficiency of 92%, indicating the high reversibility. The curves in the 10th and 200th cycles overlap very well, showing the good cyclic stability. The durable cyclic test (Fig. 4b) further confirms this. SnS2-G achieves a very stable cyclic performance over 200 cycles at 500 mA g 1. After 200 cycles, a high discharge capacity of 826 mA h g 1 is retained, showing high capacity retention. The good cyclic stability should be assigned to the 2D feature of the hybrid SnS2-G and the good flexibility of graphene substrates, both of which could effectively buffer the volume changes and thus assuring the good cyclic stability. The rate test (Fig. 4c) is conducted between 0.5 and 8 A g 1. Specific capacities of 854, 780, 728, 625, and 498 mA h g 1 can be obtained at 0.5, 1, 2, 4, and 8 A g 1, respectively, delivering excellent rate capability. The combined advantages are responsible for this, including large surface area of 2D hybrids, graphene with high electrical conductivity, and the 3D architecture for convenient electrolyte infiltration and smooth electron/ion transfer. A high capacity of 796 mA h g 1 can be recovered when the current density decreases back to 0.5 A g 1, revealing high stability and reversibility of SnS2-G.
4. Conclusions In summary, 3D framework composed of 2D hybrid few-layer SnS2 nanoplates and graphene has been prepared via solvothermal process. Such specific 3D architecture possesses combined advantages for electrochemical lithium storage, including (1) 2D hybrids supply high surface area for active materials/electrolyte contact and structural stability to accommodate the volume changes; (2) tight contact between SnS2 and graphene assures the
Fig. 1. Schematic formation of 3D architecture assembled by 2D hybrids of SnS2-G.
Q. Zhang et al. / Materials Letters 185 (2016) 311–314
313
Fig. 2. (a, b) SEM images of SnS2-G. (c) SEM image and (d) the corresponding EDS mapping of Sn, S, C, and O elements. (e, f) TEM images of SnS2-G.
fast electron exchange; (3) flexible graphene could buffer the volume variation of SnS2; (4) 3D architecture facilitates the infiltration of electrolyte and fast the electron and lithium ion diffusion. Therefore, SnS2-G delivers excellent electrochemical lithium storage properties, especially high-capacity and high-rate performance, making it a promising candidate of anode material for high-performance LIBs.
Acknowledgements This work was supported by Shandong Provincial Natural Science Foundation, China (ZR2014JL015, ZR2014EMM004). Appendix A. Supplementary material Supplementary data associated with this article can be found in the online version at http://dx.doi.org/10.1016/j.matlet.2016.08.153.
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Q. Zhang et al. / Materials Letters 185 (2016) 311–314
Fig. 3. (a) XRD pattern and (b) TG analysis of SnS2-G.
Fig. 4. The electrochemical properties of SnS2-G: (a) The 1st, 2nd, 10th, and 100th cycles of galvanostatic charge-discharge profiles and (b) cyclic performance of between 0.01 and 3 V at current density of 500 mA g 1. (c) Rate capability at current densities ranging between 0.5 and 8 A g 1.
References [1] [2] [3] [4] [5]
J.M. Tarascon, M. Armand, Nature 414 (2001) 359. J. Guo, B. Jiang, X. Zhang, L. Tang, Y.H. Wen, J. Mater. Chem. A 3 (2015) 2251. J. Liu, X.W. Liu, Adv. Mater. 24 (2012) 4097. X. Zhang, B. Jiang, J. Guo, Y. Xie, L. Tang, J. Power Sources 268 (2014) 365. R. Lv, J.A. Robinson, R.E. Schaak, D. Sun, Y. Sun, T.E. Mallouk, M. Terrones, Acc. Chem. Res. 48 (2015) 56. [6] Z. Wu, B. Li, Y. Xue, J. Li, Y. Zhang, F.J. Gao, Mater. Chem. A 3 (2015) 19445. [7] J. Guo, F. Li, Y. Sun, X. Zhang, L. Tang, J. Power Sources 291 (2015) 195.
[8] J. Ma, D. Lei, X. Duan, Q. Li, T. Wang, A. Cao, Y. Mao, W. Zheng, RSC Adv. 2 (2012) 3615. [9] X. Zhang, Q. Zhang, Y. Sun, P. Zhang, X. Gao, W. Zhang, Guo, J. Electrochim. Acta 189 (2016) 224. [10] B. Luo, Y. Fang, B. Wang, J. Zhou, H. Song, L. Zhi, Energy Environ. Sci. 5 (2012) 5226. [11] K. Chang, Z. Wang, G. Huang, H. Li, W. Chen, J.Y. Lee, J. Power Sources 201 (2012) 259. [12] Q. Zhang, R. Li, M. Zhang, B. Zhang, X. Gou, Electrochim. Acta 115 (2014) 425. [13] J. Guo, B. Jiang, X. Zhang, H. Liu, J. Power Sources 262 (2014) 15.