A highly stable zinc anode protected by a corrosion inhibitor for seawater-based zinc-ion batteries

The island-based energy storage is of urgent need for the grid construction combined with renewable energy for offshore operation.The direct use of seawater as a substitute of deionized water shows its great promise for aqueous zinc-ion batteries in such a specific situation.However,the metal corrosion,dendrite growth,and hydrogen evolution stand out in the harsh seawater environment.To address these challenges,we proposed a corrosion inhibitor that was effective in the field of metal anti-corrosion,2-phosphonobutane-1,2,4-tricarboxylic acid（PBTCA）,to inhibit anode corrosion caused by Cl-and active H2O molecules by forming a stable solid electrolyte interphase（SEI） film in the seawater-based electrolyte.Besides,PBTCA can chelate with other cations present in seawater,such as Ca2+ and Mg2+,thereby preventing the aggregation and precipitation of sparingly soluble species.Under a current density of5 mA cm-2,the seawater-based zinc-ion battery exhibited an exceptional cycle life exceeding 2000 h and maintained a Coulombic efficiency of over 99.6% after 2000 cycles.Additionally,the performance of the Zn||ZVO full battery was significantly enhanced with the addition of PBTCA.This study provides a simple,low-cost,and efficient approach for making the seawater-based zinc-ion batteries useable.