Superior TNOx/HRGO hybrid anode for lithium-ion batteries

In a paper published in NANO, a team of researchers from Chengdu Development Center of Science and Technology have significantly enhanced the performance of titanium niobium oxides for lithium-ion batteries. This has applications in electric vehicles and mobile electronics.

Due to its high security and capacity, titanium niobium oxide (TNO) has gained much attention as anode material for lithium-ion batteries. Yet, its electronic conductivity is too low to have high capability at high rates. In order to improve the high-rate performance of TNO effectively, a team of researchers from Chengdu Development Center of Science and Technology, China Academy of Engineering Physics, has combined utilized crystal structure modification, particle size reduction, porous structure, and conductive-phase compositing to solve this problem. The electrochemical performance, especially high-rate performance, of the material was significantly enhanced.

Ti₂Nb₁₀O₂₉-x/HRGO hybrid was successfully fabricated by introducing vacancies into Ti₂Nb₁₀O₂₉ (TNO) and hybridizing TNO with holey reduced graphene oxide. The structure of TNO_x/HRGO is TNO_x microspheres with oxygen vacancies wrapped by gossamer-like HRGO. Electrochemical measurements confirmed that TNO_x/HRGO hybrid exhibited excellent reversible capacity of 316 mAh/g, 278 mAh/g, 242 mAh/g, 225 mAh/g, and 173 mAh/g at 1 C, 5 C, 10 C, 20 C, and 40 C, respectively. After 300 cycles at 10 C, it still has a high capacity of 238 mAh/g with a high capacity retention of 98%, revealing excellent cycling stability.

The oxygen vacancies of TNO_x and the high conductivity of HRGO can effectively enhance the electronic conductivity of the TNO_x/HRGO hybrid, and the HRGO holes are beneficial for the transmission of lithium-ion (Li⁺). The synergy effect of above features improves the rate performance of the TNO_x/HRGO hybrid. In addition, the existence of HRGO can buffer volume expansion during the insertion processes of Li⁺, which can improve cyclic stability of the TNO_x/HRGO hybrid.

In this paper, combined utilization of several methods is proved to be an effective way to improve the electrochemical performance of TNO. Ti₂Nb₁₀O_29-x/HRGO hybrid can be a potential anode material for lithium-ion storage with high security and high capacity, as well as excellent high-rate and cycle performance.

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This research was supported in part by grants from the National Natural Science Foundation of China (No. 51873240 and 51103141) and Sichuan Science and Technology Program (2019YJ0658).

Corresponding authors for this study are Wenwen Zeng (zww123100@126.com) and Haoran Zhan (zhanhenry20@gmail.com). Additional co-authors of the NANO paper are Nan Luo, Guoliang Chen, Yunfan Shang, Suyang Lu, Jun Mei, Changyu Tang, Zhoukun He.

For more insight into the research described, readers are invited to access the paper on NANO.

Caption: The morphology image and rate capability of TNO_x/HRGO, it can be seen that its structure is TNO_x microspheres wrapped by gossamer-like HRGO, and its capacity is as high as 225 mAh/g and 173 mAh/g at 20 C and 40 C, respectively.

NANO is an international peer-reviewed monthly journal for nanoscience and nanotechnology that presents forefront fundamental research and new emerging topics. It features timely scientific reports of new results and technical breakthroughs and publishes interesting review articles about recent hot issues.

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For more information, contact Tay Yu Shan at ystay@wspc.com.

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