Promoting Reversible Redox Kinetics by Separator Architectures Based on CoS2/HPGC Interlayer as Efficient Polysulfide-Trapping Shield for Li-S Batteries
Promoting Reversible Redox Kinetics by Separator Architectures Based on CoS2/HPGC Interlayer as Efficient Polysulfide-Trapping Shield for Li-S Batteries
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DOI：
10.1002/smll.202002046
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发表时间：
2020-07-22
期刊：
影响因子：
13.3
通讯作者：
Zhang, Lingzhi
中科院分区：
文献类型：
--
作者：
Hu, Qianqian;Lu, Jiqun;Zhang, Lingzhi
可溶性多硫化物的穿梭效应和缓慢转化率的主要障碍影响了锂硫（Li-S）电池的硫利用率和循环寿命。为了追求实用的高性能锂硫电池，报道了一种隔膜配置（CoS2/HPGC/中间层）作为有效的多硫化物捕获屏障。当使用功能性中间层用于锂硫电池时，这种配置具有很大的优势，特别是增强的电导率、促进的多硫化物捕获能力、加速的硫电化学。由于上述优点，该电池表现出优异的循环性能，在0.2 C下循环250次后容量为846 mAh g(-1)，相当于80.2%的高容量保持率，在1C下循环500次后容量为519 mAh g(-1)(1C = 1675 mA g(-1))。此外，优化后的隔膜在0.1C下表现出4.293 mAh cm(-2)的高初始面积容量。此外，采用CoS2/HPGC/中间层，硫电池可实现低自放电率和高达97.1%的容量保持率。这项工作提出了一种隔膜的结构工程，旨在抑制可溶性 Li2Sn 部分的溶解，同时促进硫转化动力学，从而实现耐用且高容量的锂硫电池。
Main obstacles from the shuttle effect and slow conversion rate of soluble polysulfide compromise the sulfur utilization and cycling life for lithium sulfur (Li-S) batteries. In pursuit of a practically viable high performance Li-S battery, a separator configuration (CoS2/HPGC/interlayer) as efficient polysulfide trapping barrier is reported. This configuration endows great advantages, particularly enhanced conductivity, promoted polysulfide trapping capability, accelerated sulfur electrochemistry, when using the functional interlayer for Li-S cells. Attributed to the above merits, such cell shows excellent cyclability, with a capacity of 846 mAh g(-1)after 250 cycles corresponding to a high capacity retention of 80.2% at 0.2 C, and 519 mAh g(-1)after 500 cycles at 1C (1C = 1675 mA g(-1)). In addition, the optimized separator exhibits a high initial areal capacity of 4.293 mAh cm(-2)at 0.1C. Moreover, with CoS2/HPGC/interlayer, the sulfur cell enables a low self-discharge rate with a very high capacity retention of 97.1%. This work presents a structural engineering of the separator toward suppressing the dissolution of soluble Li2Sn moieties and simultaneously promoting the sulfur conversion kinetics, thus achieving durable and high capacity Li-S batteries.