Encapsulation of Sulfur in a Hollow Porous Carbon Substrate for Superior Li‐S Batteries with Long Lifespan
Encapsulation of Sulfur in a Hollow Porous Carbon Substrate for Superior Li‐S Batteries with Long Lifespan
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DOI：
10.1002/ppsc.201300029
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发表时间：
2013-04
影响因子：
2.7
通讯作者：
Sen Xin;Ya‐Xia Yin;L. Wan;Yu‐Guo Guo
中科院分区：
文献类型：
--
作者：
Sen Xin;Ya‐Xia Yin;L. Wan;Yu‐Guo Guo
IO N Driven by an ever-increasing energy demand, the pursuit of advanced energy storage devices is ongoing. [ 1–20 ] For the nextgeneration energy storage applications, such as the transportation and the grid, a battery with high energy density and long life span is desired. [ 21 ] Lithium-sulfur (Li-S) batteries are promising candidates because of their ultrahigh energy density (theoretically 2567 W h kg −1 ), which far exceeds the commercialized LiCoO 2 -C battery (theoretically 387 W h kg −1 ), yet their short lifespans compromise their application. [ 22–25 ] The cycling problem of the Li-S battery originates from its two electrodes, i.e., the Li anode and the S cathode. On the one hand, the use of Li anode involves with the loss of lithium on each cycle, requiring excess Li and raising safety concerns for the battery due to the growth of lithium dendrite. [ 25 ] For this issue, Li-ion batteries composed of a Li 2 S cathode and a dendrite-free anode (such as Si or Sn) present a rational solution. [ 26–28 ] However, the problem with the S cathode is even worse. A conventional cyclooctasulfur (cyclo-S 8 ) cathode suffers from a low capacity, due to the insulating properties of sulfur, and a poor capacity retention, due to an irreversible loss of active sulfur upon cycling arising from the dissolution of polysulfi de intermediates (Li 2 S n , n = 4–8) in liquid electrolytes. [ 22,29,30 ] Moreover, a strong shuttling effect of the dissolved polysulfi des leads to the formation of a passivation layer (consisting of Li 2 S and Li 2 S 2 ) on the Li anode, further deteriorating the battery’s cyclability. [ 22 ] Much effort has focused on combining sulfur with various porous carbon substrates, with the hope that the porous carbon would enhance the electronic conductivity of sulfur and trap the polysulfi des. [ 31–42 ]
