Low volume fraction co-solvent electrolyte regulates the solvation structure for highly stable zinc-ion batteries

The development of zinc-ion batteries is impeded by parasitic reactions and dendrite formation on Zn anode. In this work, we address these problems using a low volume fraction 2-ethoxyethanol (ECS) cosolvent electrolyte. ECS molecules regulate the solvation structure of Zn2+, promote the generation of a solid electrolyte interphase on the surface of the Zn anode, and play a crucial role in inhibiting parasitic reactions and Zn dendrites. Therefore, the Zn symmetric battery remains stable for 1700 h at 7 mA/cm2 and 7 mA h/cm2. In addition, the Zn||Cu asymmetric battery exhibits stability over 800 cycles at 1 mA/ cm2 and 1 mA h/cm2, with an average Coulombic efficiency of 99.54%. Furthermore, the ECS co-solvent electrolyte can significantly enhance the performance of the full cell which achieves higher specific capacity and more stable cycling performance than the one with the aqueous electrolyte. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.