Carbonized Polyacrylonitrile-Stabilized SeSx Cathodes for Long Cycle Life and High Power Density Lithium Ion Batteries
Carbonized Polyacrylonitrile-Stabilized SeSx Cathodes for Long Cycle Life and High Power Density Lithium Ion Batteries
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DOI：
10.1002/adfm.201303909
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发表时间：
2014-07-01
影响因子：
19
通讯作者：
Wang, Chunsheng
中科院分区：
文献类型：
--
作者：
Luo, Chao;Zhu, Yujie;Wang, Chunsheng
将硫化硒(SeS_2)与聚丙烯腈(PAN)的混合物在600℃真空条件下进行热处理，实现了硫化硒(SeS_X)/碳化聚丙烯腈(CPAN)复合材料的简便合成。在碳化的PAN中，SeSx分子被含N的碳(环)结构限制，以减轻多硫化物和多硒中间体在碳酸盐基电解液中的溶解。此外，SeSx/CPAN电极在第一次循环中形成的固体电解质界面(SEI)进一步阻止了多硫和多硒中间体的溶解。CPAN基质和SEI层对SeSx的协同限制使得SeSx/CPAN复合材料可以在低成本的碳酸盐基电解液(EC/DEC中的LiPF 6)中进行充放电，具有长循环稳定性和高倍率能力。在600 mAg(-1)的电流密度下，1200次循环的可逆容量保持在780mAhg(-1)。当电流密度增加到6Ag(-1)时，在60 mA g(-1)时仍能保持50%的容量。SeSx/CPAN复合材料优异的电化学性能表明，它是一种很有前途的长循环寿命和高功率密度锂离子电池正极材料。这是首次报道硫化硒基正极材料的长循环稳定性和高倍率性能。
A facile synthesis of selenium sulfide (SeSx)/carbonized polyacrylonitrile (CPAN) composites is achieved by annealing the mixture of SeS2 and polyacrylonitrile (PAN) at 600 degrees C under vacuum. The SeSx molecules are confined by N-containing carbon (ring) structures in the carbonized PAN to mitigate the dissolution of polysulfide and polyselenide intermediates in carbonate-based electrolyte. In addition, formation of solid electrolyte interphase (SEI) on the surface of SeSx/CPAN electrode in the first cycle further prevents polysulfi de and polyselenide intermediates from dissolution. The synergic restriction of SeSx by both CPAN matrix and SEI layer allows SeSx/CPAN composites to be charged and discharged in a low-cost carbonate-based electrolyte (LiPF 6 in EC/DEC) with long cycling stability and high rate capability. At a current density of 600 mA g(-1), it maintains a reversible capacity of 780 mAh g(-1) for 1200 cycles. Moreover, it retains 50% of the capacity at 60 mA g(-1) even when the current density increases to 6 A g(-1). The superior electrochemical performance of SeSx /CPAN composite demonstrates that it is a promising cathode material for long cycle life and high power density lithium ion batteries. This is the first report on long cycling stability and high rate capability of selenium sulfide-based cathode material.