Aqueous proton batteries (H-ion batteries) hold the potential to fill the gap between batteries and capacitors but suffer from severe electrode material corrosion caused by caustic acid electrolytes. Here, we report a mildly acidic proton battery in which an interfacial functionalization technique together with an ultradiluted H₂SO₄ electrolyte (0.01 M) achieves stable cycle performance of MoO₃ anode materials. The surface functionalization, specifically hydroxyl and carboxyl groups grafted on the interface of MoO₃ electrodes, facilitates successive adsorption and insertion of H⁺ and/or H₃O⁺ even in proton-deficient electrolytes. The usage of mildly acidic electrolytes obviates the corrosion challenge, achieving promising stable cycle performance of MoO₃ that otherwise rapidly loses capacity in strong acids. The MoO₃//0.01 M H₂SO₄//CuFe-TBA mildly acidic full battery delivers 109.1 mAh g^–1 capacity after long cycling with 91.18% capacity retention. This work opens an avenue for the rational design of low-corrosion and long-life aqueous proton batteries.

中文翻译：

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通过表面功能化实现弱酸性质子电池

水性质子电池（H离子电池）有潜力填补电池和电容器之间的空白，但会遭受苛性酸电解质引起的严重电极材料腐蚀。在这里，我们报道了一种弱酸性质子电池，其中界面功能化技术与超稀释的H ₂ SO ₄电解质（0.01 M）一起实现了MoO ₃负极材料的稳定循环性能。表面官能化，特别是接枝在MoO ₃电极界面上的羟基和羧基，甚至在缺乏质子的电解质中也有利于H ⁺和/或H ₃ O ⁺的连续吸附和插入。弱酸性电解质的使用消除了腐蚀挑战，实现了MoO ₃有前景的稳定循环性能，否则MoO 3 在强酸中会迅速丧失容量。 MoO ₃ //0.01 MH ₂ SO ₄ //CuFe-TBA弱酸性全电池在长时间循环后可提供109.1 mAh g ^–1容量，容量保持率为91.18%。这项工作为低腐蚀和长寿命水质子电池的合理设计开辟了一条途径。