Liu Yong, Wei Huijie, Wang Chao, Wang Fei, Wang Haichao, Zhang Wanhong, Wang Xianfu, Yan Chenglin, Kim Bok H, Ren Fengzhang
The Key Laboratory of Henan Province on Nonferrous Metallic Materials Science and Fabrication Technology, Collaborative Innovation Center of Nonferrous Metals of Henan Province, School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang, China.
Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies, Collaborative Innovation Center of Suzhou Nano Science and Technology, College of Physics, Optoelectronics and Energy, Soochow Institute for Energy and Materials Innovations, Soochow University, Suzhou, China.
Front Chem. 2018 Aug 23;6:236. doi: 10.3389/fchem.2018.00236. eCollection 2018.
Due to the cost-effectiveness of sodium source, sodium-ion batteries (SIBs) have attracted considerable attention. However, SIBs still have some challenges in competing with lithium-ion batteries for practical applications. Particularly, the high rate capability and cycling stability are posing big problems for SIBs. Here, nitrogen-doped carbon-coated WS nanosheets (WS/NC) were successfully synthesized by a high-temperature solution method, followed by carbonization of polypyrrole. When used as anode electrodes for SIBs, WS/NC composite exhibited high-rate capacity at 386 and 238.1 mAh g at 50 and 2,000 mA g, respectively. Furthermore, even after 400 cycle, the composite electrode could still deliver a capacity of ~180.1 mAh g at 1,000 mA g, corresponding to a capacity loss of 0.09% per cycle. The excellent electrochemical performance could be attributed to the synergistic effect of the highly conductive nature of the nitrogen-doped carbon-coating and WS nanosheets. Results showed that the WS/NC nanosheets are promising electrode materials for SIBs application.
由于钠源的成本效益，钠离子电池（SIBs）已引起了相当大的关注。然而，SIBs在与锂离子电池竞争实际应用方面仍面临一些挑战。特别是，高倍率性能和循环稳定性给SIBs带来了大问题。在此，通过高温溶液法成功合成了氮掺杂碳包覆的WS纳米片（WS/NC），随后对聚吡咯进行碳化。当用作SIBs的负极时，WS/NC复合材料在50和2000 mA g下分别表现出386和238.1 mAh g的高倍率容量。此外，即使经过400次循环，复合电极在1000 mA g下仍能提供约180.1 mAh g的容量，对应于每循环0.09%的容量损失。优异的电化学性能可归因于氮掺杂碳涂层和WS纳米片的高导电性的协同效应。结果表明，WS/NC纳米片是用于SIBs应用的有前途的电极材料。
