The Zn/Co₃O₄ battery is one of the few aqueous electrolyte batteries with a potential >2 V voltage. Unfortunately, so far, all reported Zn/Co₃O₄ batteries are using an alkaline electrolyte, resulting in poor cycling stability and environmental problems. Here, we report a Co(III) rich-Co₃O₄ nanorod material with vastly improved electrochemical kinetics. Zn/Co(III) rich-Co₃O₄ batteries can work well in ZnSO₄ with a CoSO₄ additive aqueous solution as a mild electrolyte, delivering a high voltage of 2.2 V, a capacity of 205 mA h g⁻¹ (Co₃O₄) and an extreme cycling stability of 92% capacity retention even after 5000 cycles. Further mechanistic study reveals a conversion reaction between in situ formed CoO and Co₃O₄, which has never been observed in an alkaline Zn/Co₃O₄ battery. Subsequently, a flexible solid-state battery is constructed and reveals high flexibility and a high energy density of 360.8 W h kg⁻¹ at a current density of 0.5 A g⁻¹. Our research initiates the first Zn/Co₃O₄ battery working in a mild electrolyte, resulting in excellent electrochemical performance. It also indicates that the electrochemical kinetics can be effectively enhanced by fine tuning the atomic structure of electrode materials, opening a new door to improve the performance of aqueous electrolyte batteries.

中文翻译：

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通过富含Co（iii）的电极启动具有2.2 V高压和5000次循环寿命 的温和的Co ₃ O ₄ / Zn水性电解质电池†

Zn / Co ₃ O ₄电池是电势> 2 V的少数水性电解质电池之一。不幸的是，到目前为止，所有报道的Zn / Co ₃ O ₄电池都使用碱性电解液，导致循环稳定性差和环境问题。在这里，我们报告了一种富含Co（III）的Co-Co ₃ O ₄纳米棒材料，其电化学动力学得到了极大的改善。富含Zn / Co（III）的Co ₃ O ₄电池可以在ZnSO _4中很好地工作，并使用CoSO ₄添加剂水溶液作为温和的电解质，可提供2.2 V的高压，容量为205 mA hg^-1（Co ₃ O ₄）和极高的循环稳定性，即使经过5000次循环仍可保持92％的容量。进一步的机理研究揭示了原位形成的CoO和Co ₃ O ₄之间的转化反应，这在碱性Zn / Co ₃ O ₄电池中从未观察到。随后，构造柔性固态电池，并且在0.5 A g ^-1的电流密度下显示出高柔性和360.8 W h kg ^-1的高能量密度。我们的研究引发了第一个Zn / Co ₃ O ₄电池在温和的电解液中工作，因此具有出色的电化学性能。这也表明，通过微调电极材料的原子结构，打开新的门来改善水性电解质电池的性能，可以有效地增强电化学动力学。