Orthorhombic MoO₃ (α-MoO₃) with multivalent redox couple of Mo⁶⁺/Mo⁴⁺ and layered structure is a promising cathode for rechargeable aqueous Zn-ion batteries (AZIBs). However, pure α-MoO₃ suffers rapid capacity decay due to the serious dissolution and structural collapse. Meanwhile, the growth of byproduct and dendrite on the anode also lead to the deterioration of cyclic stability. This article establishes the mechanism of proton intercalation into MoO₃ and proposes a joint strategy combining structural modification with electrolyte regulation to enhance the cyclic stability of MoO₃ without sacrificing the capacity. In ZnSO₄ electrolyte with Al₂(SO₄)₃ additive, TiO₂ coated oxygen-deficient α-MoO₃ (MoO_3-x@TiO₂) delivers a reversible capacity of 93.2 mA h g⁻¹ at 30 A g⁻¹ after 5000 cycles. The TiO₂ coating together with the oxygen deficiency avoids structural damage while facilitating proton diffusion. Besides, the additive of Al₂(SO₄)₃, acting as a pump, continuously supplements protons through dynamic hydrolysis, avoiding the formation of Zn₄SO₄(OH)₆·xH₂O byproducts at both MoO_3-x@TiO₂ and Zn anode. In addition, Al₂(SO₄)₃ additive facilitates uniform deposition of Zn owing to the tip-blocking effect of Al³⁺ ion. The study demonstrates that the joint strategy is beneficial for both cathode and anode, which may shed some light on the development of AZIBs.

中文翻译：

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结合结构修饰和电解质调节，实现 MoO3-x@TiO2 作为水系锌离子电池阴极的长期循环稳定性

具有Mo ⁶⁺ /Mo ⁴⁺多价氧化还原对和层状结构的斜方MoO ₃ ( α -MoO ₃ )是可充电水系锌离子电池(AZIBs)的有前景的正极。然而，纯α -MoO ₃由于严重的溶解和结构崩溃而遭受快速的容量衰减。同时，负极上副产物和枝晶的生长也会导致循环稳定性恶化。本文建立了质子嵌入MoO ₃的机制，并提出了结构修饰与电解质调节相结合的联合策略，以在不牺牲容量的情况下增强MoO _{3的循环稳定性。}在含有 Al ₂ (SO ₄ ) ₃添加剂的ZnSO ₄电解质中，TiO ₂涂层的缺氧α -MoO ₃ (MoO _3-x @TiO ₂ )在 30 A g ^-1下可提供 93.2 mA hg ^-1的可逆容量5000 次循环。TiO ₂涂层与缺氧一起避免了结构损坏，同时促进质子扩散。_{此外，Al 2} (SO ₄ ) ₃添加剂作为泵，通过动态水解不断补充质子，避免了MoO _3-x @TiO中Zn ₄ SO ₄ (OH) ₆ ·xH _{2 O副产物的形成2}、锌阳极。此外，由于Al ³⁺离子的尖端阻挡效应， Al ₂ (SO ₄ ) ₃添加剂有利于Zn的均匀沉积。研究表明，联合策略对正极和负极都有好处，这可能为 AZIB 的发展提供一些启示。