Lin Chunfu, Deng Shengjue, Kautz David J, Xu Zhihao, Liu Tao, Li Jianbao, Wang Ning, Lin Feng
State Key Laboratory of Marine Resource Utilization in South China Sea, College of Materials and Chemical Engineering, Hainan University, Haikou, 570228, China.
Department of Chemistry, Virginia Tech, Blacksburg, VA, 24061, USA.
Small. 2017 Dec;13(46). doi: 10.1002/smll.201702903. Epub 2017 Oct 17.
Ti-Nb-O binary oxide materials represent a family of promising intercalating anode materials for lithium-ion batteries. In additional to their excellent capacities (388-402 mAh g ), these materials show excellent safety characteristics, such as an operating potential above the lithium plating voltage and minimal volume change. Herein, this study reports a new member in the Ti-Nb-O family, Ti Nb O , as an advanced anode material. Ti Nb O porous spheres (Ti Nb O -S) exhibit a defective shear ReO crystal structure with a large unit cell volume and a large amount of cation vacancies (0.85% vs all cation sites). These morphological and structural characteristics allow for short electron/Li -ion transport length and fast Li -ion diffusivity. Consequently, the Ti Nb O -S material delivers significant pseudocapacitive behavior and excellent electrochemical performances, including high reversible capacity (326 mAh g at 0.1 C), high first-cycle Coulombic efficiency (87.5%), safe working potential (1.67 V vs Li/Li ), outstanding rate capability (223 mAh g at 40 C) and durable cycling stability (only 0.032% capacity loss per cycle over 200 cycles at 10 C). These impressive results clearly demonstrate that Ti Nb O -S can be a promising anode material for fast-charging, high capacity, safe and stable lithium-ion batteries.
Ti-Nb-O二元氧化物材料是一类很有前景的用于锂离子电池的插层阳极材料。除了具有出色的容量（388 - 402 mAh g）外，这些材料还表现出优异的安全特性，如工作电位高于锂金属沉积电压且体积变化最小。在此，本研究报道了Ti-Nb-O家族的一个新成员Ti Nb O 作为一种先进的阳极材料。Ti Nb O 多孔球（Ti Nb O -S）呈现出具有大晶胞体积和大量阳离子空位（相对于所有阳离子位点为0.85%）的缺陷型剪切ReO晶体结构。这些形态和结构特征使得电子/锂离子传输长度短且锂离子扩散速率快。因此，Ti Nb O -S材料表现出显著的赝电容行为和优异的电化学性能，包括高可逆容量（在0.1 C时为326 mAh g）、高首次循环库仑效率（87.5%）、安全的工作电位（相对于Li/Li 为1.67 V）、出色的倍率性能（在40 C时为223 mAh g）以及持久的循环稳定性（在10 C下200次循环中每循环容量损失仅0.032%）。这些令人印象深刻的结果清楚地表明，Ti Nb O -S可以成为用于快速充电、高容量、安全稳定的锂离子电池的一种有前景的阳极材料。
