The performance of Zn–Co batteries is hindered by some critical issues, such as the low electric conductivity and poor valence-change ability, restricting the utilization of the active material. This study aims at improving the electrochemical performance of the battery via substituting Ni on the Co₃O₄ electrode. A novel multiple self-assembled nanowire-nanosheet structure is constructed with the substitution of 10% Ni, the high electric conductivity and decent valence change-ability push the electrode to the top-tier among the reported Zn–Co batteries, including the high capacity of 272 mAh g⁻¹, high energy density of 448 Wh kg⁻¹, and excellent rate performance with a capacity retention ratio of 72.5% after even 40-fold increase of the current density. In terms of the cycle stability, it can operate well with a capacity retention ratio of 85.3% before the 1000th cycle, while dramatically decay in the subsequent cycles. More importantly, to illuminate the role of Ni substitution on the capacity decay, a systematic investigation on the Ni substituted Co₃O₄ electrode is conducted for the first time. The capacity decay mechanism is proposed as the decreased low valence species, microstructure collapse, and irreversible phase transition with an increase of the Ni substitution ratio. This work offers insights to develop high-performance and durable electrodes for Zn–Co batteries.

Zn-Co电池的性能受到一些关键问题的阻碍，例如低电导率和差的化合价，限制了活性材料的利用。这项研究旨在通过将Ni替换为Co ₃ O ₄电极来改善电池的电化学性能。用10％的镍替代构建了新型的多重自组装纳米线-纳米片结构，其高电导率和体面的价变化能力将电极推到了报道的Zn-Co电池中的顶级位置，包括高容量272 mAh g ^-1的高能量密度，448 Wh kg ^-1的高能量密度，甚至在电流密度增加40倍之后，容量保持率为72.5％的出色速率性能。就循环稳定性而言，它可以在第1000个循环之前以85.3％的容量保持率很好地运行，而在随后的循环中则急剧下降。更重要的是，为了阐明Ni取代对容量衰减的作用，首次对Ni取代的Co ₃ O ₄电极进行了系统的研究。提出了容量衰减机理，即随着镍取代率的增加，低价态物种减少，微观结构崩溃和不可逆相变。这项工作为开发用于Zn-Co电池的高性能耐用电极提供了见识。