Graphdiyne Oxide-Enabled Solid-State Proton Battery Exhibiting Superior Rate Capability

Proton batteries are emerging as a promising next-generation energy storage technology, featuring high safety, superior power density, and excellent stability. However, the development of solid-state electrolytes with high proton conductivity remains a significant challenge. Herein, graphdiyne oxide (GDYO) is proposed as a novel solid-state electrolyte for proton batteries for the first time. By constructing a three-dimensional hydrogen bonding network with phosphoric acid, the resulting GDYO@H₃PO₄ electrolyte effectively addresses the low conductivity issue of conventional solid-state electrolytes at room temperature. Fourier-transform infrared (FTIR) spectroscopy and solid-state fluorescence spectroscopy confirm the formation of an interconnected hydrogen bonding network between GDYO sheets and H₃PO₄, facilitating efficient proton transport via a hopping transport mechanism. The assembled hydrous vanadium hexacyanoferrate//MoO₃ (VHCF//MoO₃) full solid-state proton battery demonstrates superior rate capability, retaining 53.6% of its capacity retention at an ultrahigh charge-discharge rate of 50C. Furthermore, the battery delivers remarkable cycling stability with a specific capacity of 102.2 mAh g^{- 1} and 90.2% capacity retention after 4500 cycles, significantly outperforming state-of-the-art systems. This research will provide a new way to construct solid-state proton battery with long cycling stability and high performance, and highlight the exceptional potential of GDYO as a molecular-level design platform for advanced electrocatalysts in solid-state batteries.