Structural unsteadiness and limited electrochemical kinetics upon cycling seriously impede further applications of birnessite cathodes for rechargeable aqueous zinc‑ion batteries (ZIBs), even though they have high voltage platforms and distinctively layered structures for preferable (de)intercalation of zinc ions. Herein, yolk-shell structured K-birnessite (K_0.48Mn₂O₄·0.49H₂O)@mesoporous carbon nanospheres (KMOH@C) with rich oxygen vacancies are synthesized for the first time with a two-step diffusion-driven strategy of hydrothermal synthesis followed by etching with KOH. The transport of reaction ions is regulated by surface charge and pore structure of the carbon shells, thus K-birnessite is preciously transferred into the hollow mesoporous carbon (HMC) nanospheres. Furthermore, the etching effect of KOH and the confinement effect of HMC nanospheres generate intercalated K⁺ and abundant oxygen vacancies into KMOH, leading to an excellent electrochemical kinetics. Meanwhile, HMC nanospheres also endow rapid electron/ion transport and stabilize the crystal structure of K-birnessite. Therefore, KMOH@C exhibits superior electrochemical performances with high reversible capacities of 412.7 and 122.2 mA h g^‒1 at 0.5 and 10.0 A g^‒1 than reported cathodes, respectively. Moreover, an exceptional cyclability of 129.6 mA h g^‒1 even after 6000 cycles at 3.0 A g^‒1 is achieved, making the KMOH@C cathode highly competitive for eco-friendly aqueous ZIBs.

循环时的结构不稳定和有限的电化学动力学严重阻碍了水钠锰矿正极在可充电水性锌离子电池（ZIB）中的进一步应用，尽管它们具有高压平台和独特的层状结构，可更好地（脱）嵌入锌离子。其中，蛋黄壳结构的 K-水钠锰矿 (K _0.48 Mn ₂ O ₄ ·0.49H ₂首次通过水热合成的两步扩散驱动策略合成了具有丰富氧空位的 O)@介孔碳纳米球 (KMOH@C)，然后用 KOH 蚀刻。反应离子的传输受碳壳表面电荷和孔结构的调节，因此钾水钠锰矿被宝贵地转移到中空介孔碳（HMC）纳米球中。此外，KOH 的蚀刻效应和 HMC 纳米球的限制效应会产生插入的 K ⁺和丰富的氧空位进入 KMOH，导致优异的电化学动力学。同时，HMC纳米球还赋予了快速的电子/离子传输并稳定了K-水钠锰矿的晶体结构。因此，与报道的正极相比，KMOH@C 表现出优异的电化学性能，在 0.5 和 10.0 A g ^{‒1 时}具有 412.7 和 122.2 mA hg ^{‒1 的}高可逆容量。此外，即使在 3.0 A g ^{‒1 下}循环 6000 次后，也实现了 129.6 mA hg ^‒1的优异循环性能，使 KMOH@C 正极在生态友好型水性 ZIB 中具有很强的竞争力。