Dynamic molecular adsorption interface strategy for stable aluminum batteries

Rechargeable aluminum batteries (RABs) are potential candidates for large-scale energy storage devices due to their high energy density, inherent safety, and low cost. However, the corrosion of ionic liquid (IL) electrolyte and the growth of dendrite have severely restricted the application and development of RABs. Herein, an effective strategy of dynamic molecular adsorption interface is proposed for the directional modulation of the electrode/electrolyte interface by introducing cetyltrimethyl-ammonium chloride (CTAC) additives into electrolyte to inhibit corrosion and Al dendrite growth. The preferentially adsorbed CTAC molecular layer not only induces uniform Al plating/stripping, but also its amphiphilic molecular structure promotes ions migration and diffusion by improving electrode/electrolyte interfacial wettability. Benefiting from the interface optimization of CTAC, the assembled Al//Al symmetric battery were stably cycled for more than 1200 h at 3 mA cm−2 with 1 mAh cm−2. The specific capacity of the Al//FG full battery increased by 10.5% after 600 cycles (from 95 mAh g−1 to 105 mAh g−1 at 0.5 A g−1), much better than that of the pure IL electrolyte (380 cycles start to decay). This effective strategy of dynamic molecular adsorption interface construction can provide theoretical reference and practical guidance for interface modification and adjustment of other batteries electrolyte.