Stable aluminum metal anodes with high ionic conductivity and high aluminophilic site

Metal aluminum is one of the ideal choices for the negative electrode material of the next generation energy storage batteries due to its high safety, low cost, and high theoretical capacity. However, the dendritic growth caused by the uneven electrode/electrolyte interface during the continuous metal electroplating/stripping process severely restricts its commercial application. In this work, an aluminum metal anode with the stable electrode/electrolyte interface has been prepared by a simple boiling water treatment followed by phosphoric acid immersion (BPA@Al anodes). The results indicated that the BPA@Al anode has the following advantages: (1) High ion conductivity accelerates the ion transport speed of the electrode/electrolyte interface; (2) High aluminum affinity reduces the activation energy of the reaction; (3) The uniform ion concentration distribution suppresses the growth of dendrites; (4) Fast charge transfer enables the battery to maintain better rate performance. Symmetrical cell using BPA@Al anodes maintains stable cycling for more than 7000 cycles at the current density of 10 mA·cm−2. In addition, when the areal loading of the cathode material is 22.5 mg·cm−2, the full battery assembled with BPA@Al anode can stably cycle for more than 1400 h. The design principles and mechanism analysis in this study can provide theoretical basis and practical reference for exploring high safety and high stability aluminum anodes.