# A Self-Decoupling Multimodal Sensor for Enhanced Early Warning of Lithium-Ion Battery Thermal Runaway

## TL;DR

This paper introduces a compact, insect-inspired sensor that can detect multiple signals simultaneously to improve early warning of battery overheating.

## Contribution

A self-decoupling multimodal sensor with orthogonal output signals for strain, temperature, and gas detection in lithium-ion batteries.

## Key findings

- The sensor reliably decouples strain and temperature signals over a wide temperature range.
- It enables real-time monitoring of LIBs during normal operation and thermal runaway events.
- Integration with a multiphysics model allows reconstruction of thermal-mechanical evolution.

## Abstract

Lithium-ion batteries (LIBs) are central to sustainable energy systems but are vulnerable to thermal runaway (TR), necessitating robust safety monitoring. Conventional single-sensor systems cannot decouple the coupled electrochemical, thermal, and mechanical processes, while existing multimodal sensors suffer from signal cross-talk and large footprints in practical applications. Here, we introduce an insect-inspired, self-decoupling multimodal sensor, fabricated via maskless laser direct writing, that leverages distinct sensing mechanisms and orthogonal output signals for simultaneous strain, temperature, and gas detection. The sensor achieves reliable intrinsic decoupling of strain and temperature over 20 to 110 °C, along with an independent gas response. Seamlessly integrated onto lithium iron phosphate (LiFePO4) cells, it captures real-time multimodal data during both normal and TR events. Coupled with a bespoke multiphysics model, this platform reconstructs the thermal–mechanical evolution of LIBs. Our work provides a compact and durable strategy for precise real-time monitoring and early warning of battery failure.