State Key Laboratory of Mechanics and Control of Mechanical Structures, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
Dalton Trans. 2023 Feb 14;52(7):1919-1926. doi: 10.1039/d2dt03810b.
Ingenious morphology design and doping engineering have remarkable effects on enhancing conductivity and reducing volume expansion, which need to be improved by transition metal oxides serving as anode materials for lithium-ion batteries. Herein, S-FeO@C nano-spindles with a hierarchical porous structure are obtained by carbonizing MIL-88B@PDA and subsequent high-temperature S-doping. Kinetic analysis showed that S-doping increases capacitive contribution, enhances charge transfer capability and accelerates Li diffusion rate. Therefore, the S-FeO@C electrode exhibits superior lithium storage performance with a remarkable specific capacity of 1014.4 mA h g at 200 mA g, ultrahigh rate capability of 513.1 mA h g at 5.0 A g, and excellent cycling stability of 842.3 mA h g at 1.0 A g after 500 cycles. Moreover, the size of S-FeO@C particles barely changed after 50 cycles, indicating an extremely low volume expansion, related to the carbon shell, fine FeO nanoparticles, abundant voids inside, and improved kinetics. This strategy can be applied to other metal oxides for synthesizing anodes with high-rate capability and low volume expansion.
巧妙的形态设计和掺杂工程对提高导电性和减少体积膨胀有显著的效果，这需要通过过渡金属氧化物作为锂离子电池的阳极材料来改善。在此，通过碳化 MIL-88B@PDA 和随后的高温 S 掺杂，得到了具有分级多孔结构的 S-FeO@C 纳米纺丝体。动力学分析表明，S 掺杂增加了电容贡献，提高了电荷转移能力，加速了 Li 扩散速率。因此，S-FeO@C 电极表现出优异的储锂性能，在 200 mA g 时具有显著的比容量为 1014.4 mA h g，在 5.0 A g 时具有超高的倍率性能为 513.1 mA h g，在 1.0 A g 时经过 500 次循环后具有优异的循环稳定性为 842.3 mA h g。此外，S-FeO@C 颗粒的尺寸在 50 次循环后几乎没有变化，表明体积膨胀极低，这与碳壳、细小的 FeO 纳米颗粒、内部丰富的空隙和改善的动力学有关。该策略可应用于其他金属氧化物，以合成具有高倍率性能和低体积膨胀的阳极材料。
