Li Xiaona, Liang Jianwen, Luo Jing, Wang Changhong, Li Xia, Sun Qian, Li Ruying, Zhang Li, Yang Rong, Lu Shigang, Huang Huan, Sun Xueliang
Department of Mechanical and Materials Engineering, University of Western Ontario, 1151 Richmond St, London, Ontario, N6A 3K7, Canada.
China Automotive Battery Research Institute Co. Ltd, 5th Floor, No. 43, Mining Building, North Sanhuan Middle Road, Beijing, 100088, China.
Adv Mater. 2019 Apr;31(17):e1808100. doi: 10.1002/adma.201808100. Epub 2019 Mar 15.
All-solid-state Li-S batteries are promising candidates for next-generation energy-storage systems considering their high energy density and high safety. However, their development is hindered by the sluggish electrochemical kinetics and low S utilization due to high interfacial resistance and the electronic insulating nature of S. Herein, Se is introduced into S cathodes by forming SeS solid solutions to modify the electronic and ionic conductivities and ultimately enhance cathode utilization in all-solid-state lithium batteries (ASSLBs). Theoretical calculations confirm the redistribution of electron densities after introducing Se. The interfacial ionic conductivities of all achieved SeS -Li PS (x = 3, 2, 1, and 0.33) composites are 10 S cm . Stable and highly reversible SeS cathodes for sulfide-based ASSLBs can be developed. Surprisingly, the SeS /Li GeP S -Li PS /Li solid-state cells exhibit excellent performance and deliver a high capacity over 1100 mAh g (98.5% of its theoretical capacity) at 50 mA g and remained highly stable for 100 cycles. Moreover, high loading cells can achieve high areal capacities up to 12.6 mAh cm . This research deepens the understanding of Se-S solid solution chemistry in ASSLB systems and offers a new strategy to achieve high-performance S-based cathodes for application in ASSLBs.
全固态锂硫电池因其高能量密度和高安全性，是下一代储能系统的理想候选者。然而，由于高界面电阻和硫的电子绝缘性质，其缓慢的电化学动力学和低硫利用率阻碍了它们的发展。在此，通过形成硒化硫固溶体将硒引入硫阴极，以改变电子和离子电导率，最终提高全固态锂电池（ASSLB）中阴极的利用率。理论计算证实了引入硒后电子密度的重新分布。所有制备的硒化硫-Li₂PS₅（x = 3、2、1和0.33）复合材料的界面离子电导率为10 S cm⁻¹。可以开发出用于硫化物基ASSLB的稳定且高度可逆的硒化硫阴极。令人惊讶的是，硒化硫/Li₂GeP₃S₆-Li₂PS₅/Li全固态电池表现出优异的性能，在50 mA g⁻¹下可提供超过1100 mAh g⁻¹的高容量（为其理论容量的98.5%），并在100次循环中保持高度稳定。此外，高负载电池可实现高达12.6 mAh cm⁻²的高面积容量。这项研究加深了对ASSLB系统中硒-硫固溶体化学的理解，并提供了一种新策略，以实现用于ASSLB的高性能硫基阴极。
