# Breaking the Thick Electrode Paradox With an in situ VS2@V2CTx MXene Heterostructure for High‐Areal‐Capacity Batteries

## TL;DR

This paper introduces a new method to create ultra-thick battery electrodes that maintain high performance and stability.

## Contribution

The novel in situ gas-phase conversion strategy creates a VS2@V2CTx MXene heterostructure for high-areal-capacity batteries.

## Key findings

- The electrode achieves an areal capacity of 13.6 mAh cm−2 with a thickness of 300 µm.
- It retains 81% capacity after 600 cycles at 2C in LiFePO4 full-cells.
- The electrode maintains 1.8 mAh cm−2 at a high current density of 6.4 mA cm−2.

## Abstract

Achieving high areal capacity is critical for advancing lithium‐ion batteries (LIBs) toward high‐energy‐density applications. However, prevailing thick electrode architectures inevitably suffer from sluggish charge transport kinetics and mechanical degradation. Here, we pioneer an in situ gas‐phase conversion strategy to directly grow metallic VS2 nanosheets on V2CTx MXene within a multi‐walled carbon nanotube (MWCNT) network. This integrated architecture simultaneously establishes interpenetrating electron/ion highways—enabling full lithiation in ultra‐thick electrodes (12‐fold higher Li+ concentration compare to the traditional electrode)—and enhances mechanical toughness, thus achieving exceptional cycling stability under high current densities. Such TMDC–MXene heterostructure exhibit an impressive specific capacity of 1046 mAh g−1 and areal capacity of 13.6 mAh cm−2, with the thickness of 300 µm, representing only 12.8% gravimetric capacity decay despite 333% increased electrode thickness. Moreover, the resulting electrode maintains excellent cycling stability, retaining a capacity of 1.8 mAh cm−2 even at high current density of 6.4 mA cm−2, alongside 81% capacity retention over 600 cycles at 2C in LiFePO4 full‐cells.

This work pioneers an in situ gas‐phase conversion strategy to construct VS2@V2Tx heterostructures within a MWCNT network. The integrated architecture establishes interpenetrating electron/ion highways, enabling an ultra‐thick electrode (300 µm) to achieve a high areal capacity of 13.6 mAh cm−2 with exceptional cycling stability, demonstrating great promise for high‐energy‐density batteries.