Eliminating Stubborn Insulated Deposition by Coordination Effect to Boost Zn Electrode Reversibility in Aqueous...

Aqueous rechargeable zinc-ion batteries (ZIBs) have recently shined in energy storage and transmission, which are due to high safety and low cost. However, the extremely stubborn by-products in the Zn anode severely inhibited the Zn²⁺ adsorption/desorption and exacerbated the dendrite formation. Herein, we report a facile strategy to eliminate inert Zn₄(OH)₆SO₄·xH₂O for the improvement of ZIBs according to the coordination effect by employing ethylenediaminetetraacetic acid-diamine (EDTA-2Na) as a coordination additive in traditional electrolyte. Zn²⁺ is coordinated with the carboxyl group of the four acetyl carboxyl groups and the N in C-N bonds, forming a new chelating structure, and thus stubborn deposition will be dissolved in the electrolyte. As a result, the discharge capacity of 102 mAh g^-1 in the ZnSO₄/Li₂SO₄ with EDTA-2Na electrolyte at a current density of 4 C and a stable cycle life with a capacity of 90.3% after 150 cycles are achieved. It has been concluded that the coordination effect strategy provides a valuable idea for solving the defects of ZIBs.