Carbon coated “zero-strain” Li₂TiSiO₅ nanowires for high-performance lithium storage

ABSTRACT

Li₂TiSiO₅ is a ‘zero-strain’ anode material with a large theoretical capacity, appropriate operation potential, and good cyclability. However, its low electronic conductivity negatively affects its practical capacity and rate performance. Herein, we improve the electrochemical performance of Li₂TiSiO₅ by carbon-coating and nanosizing dual modifications, and further explore its lithium-storage and ‘zero-strain’ mechanisms by in-situ XRD. Within 0.2–3.0 V, the carbon-coated Li₂TiSiO₅ nanowires deliver a large reversible capacity of 257 mAh g⁻¹, high rate performance with a 5000 mA g⁻¹ vs. 50 mA g⁻¹ capacity ratio of 71.6%, and excellent cyclability with 90.0% capacity retention at 5000 mA g⁻¹ over 4000 cycles. The special crystal structure of Li₂TiSiO₅ with electrochemical active TiO₆ octahedra surrounded by inactive SiO₄ and LiO₆ polyhedra can effectively strengthen the volume-buffering capability, resulting in the ‘zero-strain’ behaviour with a tiny lattice-volume change of only 0.41%. Therefore, this dual-modified Li₂TiSiO₅ material has great practicability for high-performance lithium storage.

KEYWORDS:

• Li₂TiSiO₅
• dual modification
• electrochemical property
• in-situ XRD
• anode

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10667857.2023.2204292.