Among potential anodes for aqueous proton batteries (APBs), metal oxide offers high theoretical capacity but suffers from a sluggish desolvation process that limits cycling stability and capacity. Here we take MoO3 as an example to develop a spin-engineering strategy for accelerating the desolvation by atomic doping of trace rhenium (Re-MoO3, 1.8 at % Re per MoO3 unit). The induced spin polarization, triggered by spin exchange interaction, reconstructs the electronic structure of the terminal O site, optimizing the charge transfer to significantly accelerate desolvation kinetics. Herein, Re-MoO3 provides a high reversible capacity of 294 mAh g–1, which is 40% higher than that of MoO3, outperforming the previously reported Mo-based electrode in an aqueous electrolyte, to the best of our knowledge. Moreover, benefiting from promptly removing the solvated H2O and the consequent alleviated Mo dissolution, Re-MoO3 exhibits prominent cycling stability, retaining 98% capacity over 1000 cycles, ∼20 times higher than that of pure MoO3 (5%). An exceptionally low average capacity fade of 0.0033% per cycle is observed over 10,000 cycles. The full cell provides a maximum energy density of 41.1 Wh kg–1 at room temperature, retaining negligible energy density loss (40.8 Wh kg–1) and a high-power output of 17.1 kW kg–1 at – 40 °C owing to the accelerated desolvation process.
Gao et al. (Thu,) studied this question.