An Anode‐Free Potassium‐Metal Battery Enabled by a Directly Grown Graphene‐Modulated Aluminum Current Collector

作者：Yu Zhao, Bing-Zhi Liu, Yuyang Yi, Xueyu Lian, Menglei Wang, Shuo Li, Xianzhong Yang, Jingyu Sun · 发表于：Advances in Materials · 年份：2022 · DOI：10.1002/adma.202202902 · 被引用次数：66 · 研究领域：Medicine

Potassium (K)‐metal batteries have emerged as a promising energy‐storage device owing to abundant K resources. An anode‐free architecture that bypasses the need for anode host materials can deliver an elevated energy density. However, the poor efficiency of K plating/stripping on potassiophobic anode current collectors results in rapid K inventory loss and a short cycle life. Herein, commercial Al foils are decorated with an ultrathin graphene‐modified layer (Al@G) through roll‐to‐roll plasma‐enhanced chemical vapor deposition. By harnessing strong adhesion (10.52 N m−1) and a high surface energy (66.6 mJ m−2), the designed Al@G structure ensures a highly smooth and ordered K plating/stripping process. Consequently, during K‐metal plating/stripping, Al@G can operate at a current density of up to 4.0 mA cm−2 and cyclic capacity of up to 4.0 mAh cm−2, with an ultralong lifespan of up to 1000 h at 0.5 mA cm−2 and stable cycling of up to 750 h under periodic current fluctuations of 0.1–2.0 mA cm−2. In addition, a novel anode‐free K‐metal full‐cell prototype enabled by Al@G anode current collectors is constructed, demonstrating ameliorative cyclic stability.