Promoting Proton Transport in Si‐Doped α‐MoO ₃ via Bond‐Weakening Engineering for High‐Rate and Long‐Life Aqueous Proton Batteries

Aqueous proton batteries (APBs) hold promise for high‐rate energy storage, but their development is hindered by the instability of α‐MoO 3 electrodes, which suffer from dissolution and hydrogen evolution reactions. Herein, we report a bond‐weakening engineering strategy via Si doping to boost proton transport in α‐MoO 3 . The introduced Si(IV) forms Mo–O─Si linkages, reducing electron density around oxygen and weakening O─H bonds, thereby facilitating proton desorption and migration. The optimized Mo 0.8 Si 0.2 O 3−x electrode achieves a high specific capacity of 223.03 mAh g −1 at 1 A g −1 and retains 63.57% capacity at 20 A g −1 , vastly outperforming pristine α‐MoO 3 . In a full cell with a vanadium hexacyanoferrate (VHCF) cathode, the Mo 0.8 Si 0.2 O 3−x anode exhibits exceptional cycling durability (91.87% capacity retention after 4000 cycles at 8 A g −1 ). Density functional theory calculations confirm a reduced bandgap and lower proton diffusion barrier, underscoring the potential of non‐metal doping for high‐rate proton batteries.