Authors: Qiaonan Zhu, Liwei Cheng, Xinyu Sun, Jiaqi Huang, Jiawei Wang, Shuai Dong, Mirtemir Kurbanov, Lin Guo, Hua Wang
Published: 2025-03-30
Source: Full article
AbstractLi metal, as a counter electrode, is widely used for electrode materials evaluation in coin type half‐cells. However, whether this configuration is suitable for different working conditions has often been neglected. Herein, the large resistance and high cathodic/anodic over‐potential of Li metal at low temperature are highlighted, revealing its incompetence as counter electrode on cryogenic condition. In view of this, a novel LiC6@Li composite electrode is developed as a promising substitution for electrode materials evaluation. In the LiC6@Li electrode, Li+ de‐intercalated from LiC6 preferentially due to the low interface resistance of LiC6, presenting a cathodic/anodic over‐potential of 0.05 V (67 µA cm−2) at −20 °C, which is ten times lower than that of Li metal. Moreover, the rapid lithium replenishment into LiC6 from Li metal enables a stable potential of LiC6@Li. Consequently, the LiC6@Li‐based half‐cells enabled more precise evaluation of the Li+ storage potential and specific capacities of a series of electrode materials at low temperature. As an extension, KC8@K is also successfully prepared as a superior counter electrode to K metal. This work proposes a suitable counter electrode for more accurately evaluating electrode materials at subfreezing scenarios, demonstrating the necessity of specialized electrode evaluation systems for particular operating conditions.