Universal multifunctional hydrogen bond network construction strategy for enhanced aqueous Zn2+/proton hybrid batteries

Aqueous rechargeable zinc-ion batteries (AZIBs) are in a period of vigorous development due to their unparalleled advantages, including low cost, high safety and environmentally friendly etc. However, the structural damage, dissolution, low conductivity of electrode materials and slow diffusion kinetics of Zn2+ ions carriers significantly limit the development of AZIBs. Herein, for the first time, we propose a general strategy for constructing multifunctional intramolecular hydrogen bond network through N-H∙∙∙O (NH4+) and O-H∙∙∙O (H2O) bonds while suppressing material dissolution (V, Mn species), enhancing the stability of layered structures, and accelerating the rapid diffusion of protons. To better reveal the hydrogen bond and enhanced proton transport, a range of in/ex-situ characterization techniques in conjunction with DFT calculations have been implemented. As a proof of concept, this strategy has proven to be universally applicable, with both vanadium oxide (400.6 Wh kg−1/6489.3 W kg−1, 85% over 4000 cycles) and manganese oxide (433.6 Wh kg−1/2972.8 W kg−1, 100% after 500 cycles) achieving significant electrochemical performance improvements, particularly in terms of rate performance and cycle performance, which are better than most comparable materials. The insights obtained in this study have deepened the understanding based on the hydrogen bond in AZIBs and also brought new opportunities for improving the energy density of other types of aqueous batteries in the future.