Conversion-type transition metal oxides (TMOs) anodes with fascinating high theoretical capacities are considered potential candidates for high-energy-density alkali-ion batteries. However, the tremendous advantages of conversion reaction are yet to be fully exploited due to sluggish reaction kinetics and unfavorable thermodynamics. This is especially in the case of non-layered TMOs, where high ion intercalation energy and ion diffusion barriers compared to layered TMOs impede subsequent conversion reaction, while thermodynamically stable metal-oxide bonds with high bond energies prevent efficient cleavage. This work selects MoO₂ as a typical non-layered anode of lithium-ion batteries and demonstrates that pre-intercalating K⁺ ions in MoO₂ crystal can decrease the intercalation energy, enhance the diffusion kinetics, and weaken Mo-O bonds to efficiently facilitate conversion reactions by the the density functional theory calculations and experiments. K⁺ pre-intercalated MoO₂ can deliver a higher reversible discharge specific capacity (989 mAh g⁻¹) than the pristine MoO₂ sample (720 mAh g⁻¹) at 0.2 A g⁻¹ after 100 cycles. This work provides a novel and crucial method to realize the functionality of non-layered TMOs based anodes and offers a potentially universal optimization strategy toward high-capacity alkali-ion batteries.

具有引人入胜的高理论容量的转换型过渡金属氧化物 (TMO) 阳极被认为是高能量密度碱离子电池的潜在候选者。然而，由于反应动力学缓慢和热力学不利，转化反应的巨大优势尚未得到充分发挥。尤其是在非层状 TMO 的情况下，与层状 TMO 相比，高离子嵌入能和离子扩散势垒阻碍了后续的转化反应，而具有高键能的热力学稳定的金属氧化物键阻止了有效的裂解。本工作选择 MoO ₂作为锂离子电池的典型非层状负极，并证明在 MoO _{2中预嵌入 K} ⁺离子通过密度泛函理论计算和实验，晶体可以降低插层能量，增强扩散动力学，削弱Mo-O键以有效促进转化反应。K ⁺预插层 MoO ₂在 0.2 A g ^-1循环 100 次后可提供比原始 MoO ₂样品（720 mAh g ^-1 ）更高的可逆放电比容量（989 mAh g ^{- 1 ）。}这项工作为实现基于非层状 TMO 的负极的功能提供了一种新颖且关键的方法，并为高容量碱离子电池提供了一种潜在的通用优化策略。