A synergistic vertical graphene skeleton and S–C shell to construct high-performance TiNb2O7-based core/shell arrays. Issue 41 (10th October 2018)

• Record Type: Journal Article
• Authors: Shen, Shenghui; Guo, Weihao; Xie, Dong; Wang, Yadong; Deng, Shengjue; Zhong, Yu; Wang, Xiuli; Xia, Xinhui; Tu, Jiangping
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 41(2018)
• Page Start: 20195
• Page End: 20204
• Publication Date: 2018-10-10
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8ta06858e
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : Binder-free VG/TiNb2 O7 @S–C electrodes prepared via a powerful solvothermal-electrodeposition (ST-ED) method show good high-rate performance (241 mA h g −1 /70 °C at 160C) and long high-temperature lifespan (>5000 cycles) at medium–high temperatures. Abstract : Bespoke synthesis of wide-temperature high-power electrodes is of great importance for the development of advanced power-type lithium ion batteries (LIBs). Herein, we report a powerful combined solvothermal-electrodeposition (ST-ED) method to construct titanium niobium oxide (TiNb2 O7 ) arrays sandwiched between a highly conductive vertical graphene (VG) skeleton and S–C shell forming a binder-free VG/TiNb2 O7 @S–C electrode. VG and S–C work cooperatively to establish an omnibearing conductive network on TiNb2 O7 through internal and external integration. Positive advantages including large porosity, improved conductivity and enhanced structural stability are obtained in the VG/TiNb2 O7 @S–C core/shell arrays. Consequently, excellent electrochemical high-power performance at medium–high temperature (25 to 70 °C) is demonstrated for the designed VG/TiNb2 O7 @S–C electrodes, which show a high capacity from 284 to 354 mA h g −1 at 1C, and 181 to 241 mA h g −1 at 160C as the working temperature increases from 25 to 70 °C. Additionally, a remarkable high-temperature (70 °C) cycling span is proven for the VG/TiNb2 O7 @S–C electrode with a capacity of 203 mA h g −1 at 40C after 5000 cycles. The synergistic positive effect from the VG and S–C shell is responsible for the enhancement of high-power capability. Our work paves the way for the fabrication of novel high-power electrodes for electrochemical energy storage.