# Lithium Intercalation Chemistry in TaS2 Nanosheets for Lithium-Ion Batteries Anodes

## TL;DR

Researchers developed a new TaS2 nanosheet anode for lithium-ion batteries that shows excellent cycling stability and a unique reaction mechanism.

## Contribution

The study introduces a novel TaS2 nanosheet anode with a reversible phase transition mechanism enhancing battery performance.

## Key findings

- TaS2 nanosheet anode achieved 234.6 mAh g−1 after 500 cycles at 1 A g−1.
- The anode's performance is attributed to large interlayer spacing, high conductivity, and reduced size.
- A reversible phase transition from 2H to 1T during de-lithiation improves electrochemical performance.

## Abstract

Exploring novel two-dimensional layered transitional metal dichalcogenides and elucidating their reaction mechanism are critical to designing promising anode materials for lithium-ion batteries (LIBs). Herein, a novel layered TaS2 nanosheet was obtained via a typical solid-phase reaction method followed by a simple ball-milling treatment, and first explored experimentally as an anode for LIBs. The TaS2 nanosheet anode delivered an excellent cycling stability, with 234.6 mAh g−1 after 500 cycles at 1 A g−1. The optimized performance could be attributed to the large interlayer spacing, high conductivity, and reduced size of the TaS2 nanosheet, which effectively alleviated the volume change during the reaction process and accelerated the Li+ or e− transport. Especially, the TaS2 nanosheet anode presented an unusual intercalation reaction mechanism, accompanied with a reversible phase transition from the 2H to the 1T phase during the first de-lithiation process, which is evidenced by the multiple ex situ characterizations, further revealing the enhanced electrochemical performance results from the 1T phase with the larger interlayer spacing and higher electrical conductivity. This work provides a novel insight into the intercalation reaction mechanism of TaS2, which shows potential in high-performance LIBs.