Toward reversible wide-temperature Zn storage by regulating the electrolyte solvation structure via trimethyl phosphate

Abstract

The introduction of TMP changes the coordination environment of Zn 2+ to reshape the hydrogen bond network of water. A novel strategy is established to regulate Zn 2+ -solvation shell, restraining vanadium dissolution, suppressing Zn dendrite formation and contributing to uniform deposition of Zn 2+ . • A novel Zn 2+ -solvation shell is formed via trimethyl phosphate. • Zn symmetrical battery exhibits an ultralong cyclic lifespan for 7000 h at 1 mA cm −2 . • The cathode dissolution and self-discharge of battery are efficiently suppressed. • Zn|VO 2 (B) cell possesses 97.86% capacity retention after 1200 cycles at 1 A·g −1 (0 °C). The wide-scale application of zinc-ion batteries (ZIBs) is largely restricted by dendrite formation, hydrogen evolution corrosion and capacity fading, caused by the coordinated H 2 O within the Zn 2+ -solvation shell as well as reactive active water in the bulk electrolyte. Here, one green and flame-retardant additive, trimethyl phosphate (TMP) is introduced into aqueous electrolyte systems, contributing to Zn 2+ -solvation shell reshaping and promoting the stability hydrogen bonding network of H 2 O. The strategy is significant in suppressing water-induced side reactions and dendrite growth, enabling an ultralong cycling lifespan of 7000 h at 1 mA·cm −2 and 0.5 mAh·cm −2 in Zn symmetrical cell. In addition, Zn|VO 2 (B) full cells with TMP addition exhibit an ultralong cyclic performance for 1200 cycles at 1 A·g −1 with 97.86% capacity retention even at 0 °C, which contributes to taking a step closer to commercial application. This work demonstrates the feasibility of developing electrolytes for practical ZIBs that integrate safety, sustainability and wide-temperature applications.