Huo Hanyu, Gao Jian, Zhao Ning, Zhang Dongxing, Holmes Nathaniel Graham, Li Xiaona, Sun Yipeng, Fu Jiamin, Li Ruying, Guo Xiangxin, Sun Xueliang
Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON, N6A 5B9, Canada.
State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 200050, Shanghai, China.
Nat Commun. 2021 Jan 8;12(1):176. doi: 10.1038/s41467-020-20463-y.
Solid-state batteries (SSBs) are considered to be the next-generation lithium-ion battery technology due to their enhanced energy density and safety. However, the high electronic conductivity of solid-state electrolytes (SSEs) leads to Li dendrite nucleation and proliferation. Uneven electric-field distribution resulting from poor interfacial contact can further promote dendritic deposition and lead to rapid short circuiting of SSBs. Herein, we propose a flexible electron-blocking interfacial shield (EBS) to protect garnet electrolytes from the electronic degradation. The EBS formed by an in-situ substitution reaction can not only increase lithiophilicity but also stabilize the Li volume change, maintaining the integrity of the interface during repeated cycling. Density functional theory calculations show a high electron-tunneling energy barrier from Li metal to the EBS, indicating an excellent capacity for electron-blocking. EBS protected cells exhibit an improved critical current density of 1.2 mA cm and stable cycling for over 400 h at 1 mA cm (1 mAh cm) at room temperature. These results demonstrate an effective strategy for the suppression of Li dendrites and present fresh insight into the rational design of the SSE and Li metal interface.
固态电池（SSB）因其更高的能量密度和安全性而被视为下一代锂离子电池技术。然而，固态电解质（SSE）的高电子电导率会导致锂枝晶的成核和生长。界面接触不良导致的电场分布不均会进一步促进枝晶沉积，并导致固态电池迅速短路。在此，我们提出了一种柔性电子阻挡界面屏蔽层（EBS），以保护石榴石电解质免受电子降解。通过原位取代反应形成的EBS不仅可以增加亲锂性，还能稳定锂体积变化，在反复循环过程中保持界面的完整性。密度泛函理论计算表明，从锂金属到EBS存在高电子隧穿能垒，这表明其具有出色的电子阻挡能力。EBS保护的电池在室温下表现出改善的临界电流密度，为1.2 mA cm，并且在1 mA cm（1 mAh cm）下能稳定循环超过400小时。这些结果证明了一种抑制锂枝晶的有效策略，并为固态电解质和锂金属界面的合理设计提供了新的见解。
