Optimizing SnO<sub>2−</sub><i><sub>x</sub></i>/Fe<sub>2</sub>O<sub>3</sub> Hetero‐Nanocrystals Toward Rapid and Highly Reversible Lithium Storage
Chen Hu, Ling Chen, Yanjie Hu, Aiping Chen, Long Chen, Hao Jiang, Chunzhong Li
Abstract
Abstract Engineering oxygen vacancy and boosting Li 2 O reversibility on oxides‐based electrode are of significance but remains a challenge in high‐power lithium‐ion batteries. Herein, the heterogenous SnO 2− x /Fe 2 O 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 /Fe 2 O 3 with a maximum x value has the optimal electronic structure, the metallic Fe generated from Fe 2 O 3 can markedly reduce the free energy to break Li–O bonds for accelerating subsequent delithiation process of Li 2 O. Consequently, the optimized SnO 2− x /Fe 2 O 3 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 Li 2 O reversibility.