Co-Modification of commercial TiO anode by combining a solid electrolyte with pitch-derived carbon to boost cyclability and rate capabilities

• Published in: Nanoscale advances 2020-06, Vol.2 (6), p.2531-2539
• Main Authors: Kong, Ling-Yun, An, Jing, Kang, Shu-Xian, Huang, Meng, Yang, Huan, Zhu, Hui-Ling, Qi, Yong-Xin, Bai, Xue, Lun, Ning, Bai, Yu-Jun
• Format: Article
• Language: English
• ISSN: 2516-0230
• DOI: 10.1039/d0na00192a

The bad electrochemical performance circumscribes the application of commercial TiO 2 (c-TiO 2 ) anodes in Li-ion batteries. Carbon coating could ameliorate the electronic conductivity of TiO 2 , but the ionic conductivity is still inferior. Herein, a co-modification method was proposed by combining the solid electrolyte of lithium magnesium silicate (LMS) with pitch-derived carbon to concurrently meliorate the electronic and ionic conductivities of c-TiO 2 . The homogeneous mixtures were heated at 750 °C, and the co-modified product with suitable amounts of LMS and carbon demonstrates cycling capacities of 256.8, 220.4, 195.9, 176.4, and 152.0 mA h g −1 with multiplying current density from 100 to 1600 mA g −1 . Even after 1000 cycles at 500 mA g −1 , the maintained reversible capacity was 244.8 mA h g −1 . The superior rate performance and cyclability correlate closely with the uniform thin N-doped carbon layers on the surface of c-TiO 2 particles to favor the electrical conduction, and with the ion channels in LMS as well as the cation exchangeability of LMS to facilitate the Li + transfer between the electrolyte, carbon layers, and TiO 2 particles. The marginal amount of fluoride in LMS also contributes to the excellent cycling stability of the co-modified c-TiO 2 . The bad electrochemical performance circumscribes the application of commercial TiO 2 (c-TiO 2 ) anodes in Li-ion batteries.