标题：New Insights into the Electrochemistry Superiority of Liquid Na-K Alloy in Metal Batteries
作者：Huang, Man; Xi, Baojuan; Feng, Zhenyu; Wu, Fangfang; Wei, Denghu; Liu, Jing; Feng, Jinkui; Qian, Yitai; Xiong, Shenglin
作者机构：[Huang, Man; Xi, Baojuan; Feng, Zhenyu; Wu, Fangfang; Qian, Yitai; Xiong, Shenglin] Shandong Univ, Minist Educ, Key Lab Colloid & Interface Chem, Jina 更多
通讯作者：Xiong, Shenglin;Xiong, SL;Xiong, SL;Xiong, SL
通讯作者地址：[Xiong, SL]Shandong Univ, Minist Educ, Key Lab Colloid & Interface Chem, Jinan 250100, Shandong, Peoples R China;[Xiong, SL]Shandong Univ, Sch Chem & 更多
关键词：alkali metal batteries; dendrite growth; liquid-liquid interface; Na-K; liquid alloy anode; N-doped porous carbon
摘要：The significant issues with alkali metal batteries arise from their poor electrochemical properties and safety problems, limiting their applications. Herein, TiO2 nanoparticles embedded into N-doped porous carbon truncated ocatahedra (TiO2 subset of NPCTO) are engineered as a cathode material with different metal anodes, including solid Na or K and liquid Na-K alloy. Electrochemical performance and kinetics are systematically analyzed, with the aim to determine detailed electrochemistry. By using a galvanostatic intermittent titration technique, TiO2 subset of NPCTO/NaK shows faster diffusion of metal ions in insertion and extraction processes than that of Na-ions and K-ions in solid Na and K. The lower reaction resistance of liquid Na-K alloy electrode is also examined. The higher b-value of TiO2 subset of NPCTO/NaK confirms that the reaction kinetics are promoted by the surface-induced capacitive behavior, favorable for high rate performance. This superiority highly pertains to the distinct liquid-liquid junction between the electrolyte and electrode, and the prohibition of metal dendrite growth, substantiated by symmetric cell testing, which provides a robust and homogeneous interface more stable than the traditional solid-liquid one. Hence, the liquid Na-K alloy-based battery exhibits to better cyclablity with higher capacity, rate capability, and initial coulombic efficiency than solid Na and K batteries.