Suppressed Dissolution and Enhanced Desolvation in Core–Shell MoO<sub>3</sub>@TiO<sub>2</sub> Nanorods as a High‐Rate and Long‐Life Anode Material for Proton Batteries
Chenggang Wang, Shunshun Zhao, Xinxin Song, Nana Wang, Huili Peng, Jie Su, Suyuan Zeng, Xijin Xu, Jian Yang
Abstract
Abstract Rechargeable proton batteries are attractive, because protons as a charge carrier have a small ionic radius, a lightest mass, and a high abundance on Earth. MoO 3 , as one of the promising anode materials in rechargeable proton batteries, suffers from the severe dissolution in acidic electrolytes upon cycling. Here, an ultrathin TiO 2 shell is coated on MoO 3 nanorods to suppress the detrimental dissolution during cycles. TiO 2 also lowers the desolvation energy of hydrated protons, promoting the reaction kinetics. As a result, MoO 3 @TiO 2 displays outstanding electrochemical performance, especially at high rates (171.0 mAh g −1 at 30 A g −1 ) and at high mass loadings (17 mAh cm −2 at 104 mg cm −2 ). The full cells constructed with MnO 2 deliver an energy density up to 252.9 Wh kg −1 and a power density of 18.3 kW kg −1 . Ex situ X‐ray diffraction and X‐ray photoelectron spectroscopy indicate that protons shuttle back and forth between different monoclinic phases. The results offer a simple way to achieve the high performance of MoO 3 in a diluted acidic solution.