Bimetallic Hexagonal Layered Ni–Co Sulfides with High Electrochemical Performance for All-Solid-State Lithium Batteries
Bimetallic Hexagonal Layered Ni–Co Sulfides with High Electrochemical Performance for All-Solid-State Lithium Batteries
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DOI：
10.1021/acssuschemeng.1c06035
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发表时间：
2021-12
影响因子：
8.4
通讯作者：
Mengting Zhu;Jiaming Shi;X. Xin;Jinghua Wu;X. Yao
中科院分区：
文献类型：
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作者：
Mengting Zhu;Jiaming Shi;X. Xin;Jinghua Wu;X. Yao
全固态锂(Li)电池因其在安全性方面的优势，已成为具有吸引力的储能系统技术。然而，由于电解液与电极之间的固-固接触，全固态锂电池的电化学性能受到界面问题的限制。本文合成了具有特殊六方层状结构的二元过渡金属硫化物NixCo3-xS4，并将其引入到基于硫化物电解液的全固态锂电池中。通过自由调整Ni/Co比，可以很容易地获得性能最佳的组件。此外，良好的界面结构有利于离子传输和界面稳定性，因为硫化物电解质颗粒可以铆接在六方晶片上，从而最大限度地降低固体电解质与阴极之间的接触电阻。结果表明，采用Ni0.3Co2.7S4@Li7P3S11复合正极的全固态锂电池具有更好的倍率性能和循环稳定性。在0.1A·g~(-1)的电流密度下，其比容量高达1216 mA·h·g~(-1)。即使在1A·g~(-1)的大电流下，100次循环后仍能保持510 mA·h~(-1)的大容量。
All-solid-state lithium (Li) batteries have been emerging as attractive technologies for energy storage systems due to their benefits in safety. However, the electrochemical performance of all-solid-state Li batteries is limited by the interfacial problems resulting from the solid–solid contact between electrolytes and electrodes. Here, a binary transition-metal sulfide NixCo3–xS4with a special hexagonal layered structure is synthesized and introduced into all-solid-state Li batteries based on sulfide electrolytes. By freely adjusting the Ni/Co ratio, components with optimal performance can be easily obtained. In addition, the well-designed interfacial structure is favorable for ion transport and interfacial stability because the sulfide electrolyte particles can rivet on the hexagonal platelets which can maximally reduce the contact resistance between the solid electrolytes and cathodes. As a result, the all-solid-state Li battery employing the Ni0.3Co2.7S4@Li7P3S11composite cathode exhibits enhanced rate capability and cycling stability. At a current density of 0.1 A g–1, it delivers a specific capacity as high as 1216 mA h g–1. Even under a large current of 1 A g–1, a large capacity of 510 mA h g–1can be retained after 100 cycles.