Hybrid Interface Chemistry Enabling Mixed Conducting via Ultrafast Microwave Polarization Toward Dendrite-Free Zn Anodes.

Abstract

Zn metal anodes in aqueous electrolytes suffer from interface issues including uncontrolled dendrite growth and undesired side reactions, resulting in their limited application in terms of short circuits and cell failure. Herein, a hybrid interface chemistry strategy is developed through ultrafast microwave polarization at the skin region of bare Zn. Owing to efficient Joule heating directed by abundant local hot spots at electron valleys, the rapid establishment of a dense interfacial layer can be realized within a minute. Stabilized Zn with suppressed side reactions or surface corrosion is therefore achieved due to the interfacial protection. Importantly, hybrid zincophilic sites involving laterally/vertically interconnected Cu-Zn intermetallic compound and Zn2+ -conductive oxide species ensure mixed charge conducting (denoted as CuHL@Zn), featuring uniformly distributed electric field and boosted Zn2+ diffusion kinetics. As a consequence, CuHL@Zn in symmetric cells affords lifespans of 2800 and 3200h with ultra-low polarization voltages (≈19 and 56mV) at a plating capacity of 1.0mAhcm-2 for 1 and 5mAcm-2 , respectively. The CuHL@Zn||MnO2 full cell further exhibits cycling stability with a capacity retention of over 80% for 500 cycles at 2Ag-1 .