Zhao Hang, Tian Bingbing, Su Chenliang, Li Ying
International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoeletronics, Shenzhen University, Shenzhen 518060, People's Republic of China.
ACS Appl Mater Interfaces. 2021 Feb 17;13(6):7171-7177. doi: 10.1021/acsami.0c20446. Epub 2021 Feb 2.
Lithium-sulfur (Li-S) batteries are regarded as promising secondary energy storage devices for their high energy density and low cost. The electrochemical performance of Li-S batteries is mainly determined by the efficient and reversible conversion of lithium-polysulfides to LiS when discharging and to S when charging. Herein, a catalytic strategy is proposed to accelerate the reversible conversion of S and the discharge products in Li-S batteries. This reversible transformation is achieved with active sites of single-atom iron on nitrogen- and sulfur-doped porous carbon (FeNSC). We prove that the synergy between atomically dispersed iron and doped sulfur accelerates the reversible electrochemical conversion reactions in Li-S batteries. The FeNSC/S hybrid cathode exhibits superior long-term cycling stability even at a high current density of 1C, with only 0.047% capacity decay per cycle over 1000 cycles. This study demonstrates a novel method for improving the conversion of polysulfides based on electrocatalysis strategies to ultimately obtain high-performance Li-S batteries.
锂硫（Li-S）电池因其高能量密度和低成本而被视为有前景的二次储能装置。Li-S电池的电化学性能主要取决于锂多硫化物在放电时高效且可逆地转化为LiS以及在充电时转化为S。在此，提出了一种催化策略来加速Li-S电池中S与放电产物的可逆转化。这种可逆转化通过氮硫共掺杂多孔碳上的单原子铁活性位点（FeNSC）实现。我们证明了原子分散的铁与掺杂硫之间的协同作用加速了Li-S电池中的可逆电化学转化反应。即使在1C的高电流密度下，FeNSC/S复合阴极仍表现出优异的长期循环稳定性，在1000次循环中每循环容量衰减仅0.047%。本研究展示了一种基于电催化策略改善多硫化物转化以最终获得高性能Li-S电池的新方法。
