Unprecedented and highly stable lithium storage capacity of (001) faceted nanosheet-constructed hierarchically porous TiO2/rGO hybrid architecture for high-performance Li-ion batteries

Wen-Bei Yu; Zhi-Yi Hu; Jun Jin; Min Yi; Min Yan; Yu Li; Hong-En Wang; Huan-Xin Gao; Li-Qiang Mai; Tawfique Hasan; Bai-Xiang Xu; Dong-Liang Peng; Gustaaf Van Tendeloo; Bao-Lian Su

doi:10.1093/nsr/nwaa028

Unprecedented and highly stable lithium storage capacity of (001) faceted nanosheet-constructed hierarchically porous TiO₂/rGO hybrid architecture for high-performance Li-ion batteries

Natl Sci Rev. 2020 Jun;7(6):1046-1058. doi: 10.1093/nsr/nwaa028. Epub 2020 Feb 20.

Authors

Wen-Bei Yu¹, Zhi-Yi Hu¹, Jun Jin¹, Min Yi², Min Yan¹, Yu Li¹, Hong-En Wang¹, Huan-Xin Gao³, Li-Qiang Mai¹, Tawfique Hasan⁴, Bai-Xiang Xu², Dong-Liang Peng⁵, Gustaaf Van Tendeloo⁶, Bao-Lian Su¹

Affiliations

¹ State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan, University of Technology, Wuhan 430070, China.
² Institute of Materials Science, Technische Universität Darmstadt, Darmstadt 64287, Germany.
³ Fundamental Research Department, SINOPEC Shanghai Research Institute of Petrochemical Technology, Shanghai 201208, China.
⁴ Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, UK.
⁵ Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, China.
⁶ Nanostructure Research Centre, Wuhan University of Technology, Wuhan 430070, China.

Abstract

Active crystal facets can generate special properties for various applications. Herein, we report a (001) faceted nanosheet-constructed hierarchically porous TiO₂/rGO hybrid architecture with unprecedented and highly stable lithium storage performance. Density functional theory calculations show that the (001) faceted TiO₂ nanosheets enable enhanced reaction kinetics by reinforcing their contact with the electrolyte and shortening the path length of Li⁺ diffusion and insertion-extraction. The reduced graphene oxide (rGO) nanosheets in this TiO₂/rGO hybrid largely improve charge transport, while the porous hierarchy at different length scales favors continuous electrolyte permeation and accommodates volume change. This hierarchically porous TiO₂/rGO hybrid anode material demonstrates an excellent reversible capacity of 250 mAh g^-1 at 1 C (1 C = 335 mA g^-1) at a voltage window of 1.0-3.0 V. Even after 1000 cycles at 5 C and 500 cycles at 10 C, the anode retains exceptional and stable capacities of 176 and 160 mAh g^-1, respectively. Moreover, the formed Li₂Ti₂O₄ nanodots facilitate reversed Li⁺ insertion-extraction during the cycling process. The above results indicate the best performance of TiO₂-based materials as anodes for lithium-ion batteries reported in the literature.

Keywords: (001) faceted TiO2 nanosheets; Li2Ti2O4 crystallites; porous hierarchy; reduced graphene oxide; unprecedented lithium storage capacity.