Electrocatalysis driven high energy density Li-ion polysulfide battery
Electrocatalysis driven high energy density Li-ion polysulfide battery
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DOI：
10.1016/j.electacta.2019.03.191
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发表时间：
2019-06
影响因子：
6.6
通讯作者：
A. Sawas;G. Babu;Naresh kumar Thangavel;L. Arava
中科院分区：
文献类型：
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作者：
A. Sawas;G. Babu;Naresh kumar Thangavel;L. Arava
虽然碳基多孔材料显著提高了锂硫电池的性能，但其对多硫化物的吸附能力差，反应动力学缓慢，限制了其实际应用。另一方面，锂金属的存在，特别是在高反应性多硫化物环境下，引起安全问题。在此，我们使用电催化活性阴极和金属无锂阳极来构建具有增强可逆性和安全性的锂离子多硫电池。使用铂/石墨烯复合材料稳定多硫化锂并以最小极化增强反应动力学是获得更好性能的关键，这是相对于常规金属锂以及预锂化多孔硅电极实现的。含有阴极复合材料的电催化剂在提高的比容量保持率和更好的充电/放电行为的可逆性方面与石墨烯基电极相当。此外，考虑到电活性材料的重量，金属无锂多硫化物电池显示出450 Wh kg-1的能量密度和240次充电-放电循环约70%的容量保持率的优异性能。
Though carbon-based porous materials have improved lithium-sulfur (Li-S) battery performance remarkably, the poor adsorption of polysulfides and their sluggish reaction kinetics limits them from practical application. On the other hand, the presence of lithium metal especially under the highly reactive polysulfide environment causes safety concerns. Herein, we use electrocatalytically active cathode and metallic lithium-free anode to construct Li-ion polysulfide battery with enhanced reversibility and safety. Stabilizing lithium polysulfides and enhancing the reaction kinetics with minimal polarization using platinum/graphene composite holds the key to obtaining better performance, which is realized against conventional metallic lithium as well as pre-lithiated porous silicon electrodes. The electrocatalyst containing cathode composites are comparable with graphene-based electrodes regarding enhanced specific capacity retention and better reversibility in charge/discharge behavior. Furthermore, metallic lithium-free polysulfide batteries displayed exceptional performance with an energy density of 450 Wh kg−1considering the weight of both the electroactive materials and a capacity retention of about 70% for 240 charge-discharge cycles.