Engineering oxygen vacancy and boosting Li₂O reversibility on oxides-based electrode are of significance but remains a challenge in high-power lithium-ion batteries. Herein, the heterogenous SnO_2−x/Fe₂O_3−y nanocrystals are demonstrated with tailorable x and y values enabled by a glucose-assisted spray combustion technique. Density functional theory calculations unveil the SnO_2−x/Fe₂O₃ with a maximum x value has the optimal electronic structure, the metallic Fe generated from Fe₂O₃ can markedly reduce the free energy to break Li–O bonds for accelerating subsequent delithiation process of Li₂O. Consequently, the optimized SnO_2−x/Fe₂O₃ exhibits a remarkably enhanced electrochemical reversibility and reaction kinetics. After stabilized by reduced graphene oxide, the hybrid delivers a high reversible specific capacity of 1113 mAh g⁻¹ with superior rate performance (474 mAh g⁻¹ at 20 A g⁻¹) and long cycle life (negligible loss after 500 cycles at 5 A g⁻¹), the oxygen vacancy and microstructure are well-maintained after cycles. This work provides the possibilities for skillfully regulating oxygen vacancy and meantime enhancing Li₂O reversibility.

中文翻译：

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优化 SnO2−x/Fe2O3 异质纳米晶体以实现快速和高度可逆的锂存储

在基于氧化物的电极上设计氧空位和提高 Li ₂ O 可逆性具有重要意义，但在高功率锂离子电池中仍然是一个挑战。在本文中，非均质 SnO _{2- x} /Fe ₂ O _{3- y}纳米晶体通过葡萄糖辅助喷雾燃烧技术实现了可定制的x和y值。密度泛函理论计算揭示了具有最大x值的 SnO _{2− x} /Fe ₂ O ₃具有最佳电子结构，由 Fe ₂ O ₃生成的金属 Fe可以显着降低破坏 Li-O 键的自由能，从而加速 Li ₂ O 的后续脱锂过程。因此，优化的 SnO _{2- x} /Fe ₂ O ₃表现出显着增强的电化学可逆性和反应动力学。稳定化还原氧化石墨烯之后，混合提供的1113毫安g的高可逆比容量^-1具有优异的倍率性能（474毫安克^-1在20 A G ^-1）和长的循环寿命（在5个500次循环后损失可忽略不计克^-1)，氧空位和微观结构在循环后保持良好。这项工作为巧妙调节氧空位并同时增强Li ₂ O 可逆性提供了可能性。