Yang Yang, Huang Jingxin, Cao Zhenming, Lv Zeheng, Wu Dongzhen, Wen Zhipeng, Meng Weiwei, Zeng Jing, Li Cheng Chao, Zhao Jinbao
State Key Lab of Physical Chemistry of Solid Surfaces, State-Province Joint Engineering Laboratory of Power Source Technology for New Energy Vehicle, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.
School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, P. R. China.
Adv Sci (Weinh). 2022 Feb;9(6):e2104530. doi: 10.1002/advs.202104530. Epub 2021 Dec 28.
Implementing fast-charging lithium-ion batteries (LIBs) is severely hindered by the issues of Li plating and poor rate capability for conventional graphite anode. Wadsley-Roth phase TiNb O is regarded as a promising anode candidate to satisfy the requirements of fast-charging LIBs. However, the unsatisfactory electrochemical kinetics resulting from sluggish ion and electron transfer still limit its wide applications. Herein, an effective strategy is proposed to synchronously improve the ion and electron transfer of TiNb O by incorporation of oxygen vacancy and N-doped graphene matrix (TNO @N-G), which is designed by combination of solution-combustion and electrostatic self-assembly approach. Theoretical calculations demonstrate that Li intercalation gives rise to the semi-metallic characteristics of lithiated phases (Li TNO ), leading to the self-accelerated electron transport. Moreover, in situ X-ray diffraction and Raman measurements reveal the highly reversible structural evolution of the TNO @N-G during cycling. Consequently, the TNO @N-G delivers a higher reversible capacity of 199.0 mAh g and a higher capacity retention of 86.5% than those of pristine TNO (155.8 mAh g , 59.4%) at 10 C after 2000 cycles. Importantly, various electrochemical devices including lithium-ion full battery and hybrid lithium-ion capacitor by using the TNO @N-G anode exhibit excellent rate capability and cycling stability, verifying its potential in practical applications.
传统石墨负极的锂镀层和倍率性能差等问题严重阻碍了快速充电锂离子电池（LIBs）的应用。瓦兹利-罗思相TiNbO被认为是满足快速充电LIBs要求的有前途的负极候选材料。然而，离子和电子转移缓慢导致的不理想的电化学动力学仍然限制了其广泛应用。在此，提出了一种有效的策略，通过引入氧空位和N掺杂石墨烯基体（TNO@N-G）来同步改善TiNbO的离子和电子转移，该策略是通过溶液燃烧和静电自组装方法相结合设计的。理论计算表明，锂嵌入导致锂化相（Li-TNO）的半金属特性，从而导致自加速电子传输。此外，原位X射线衍射和拉曼测量揭示了TNO@N-G在循环过程中高度可逆的结构演变。因此，在2000次循环后，TNO@N-G在10C下的可逆容量为199.0mAh/g，容量保持率为86.5%，高于原始TNO（155.8mAh/g，59.4%）。重要的是，使用TNO@N-G负极的各种电化学装置，包括锂离子全电池和混合锂离子电容器，都表现出优异的倍率性能和循环稳定性，验证了其在实际应用中的潜力。
