Key Parameters in Determining the Reactivity of Lithium Metal Battery

TL;DR

This study systematically investigates the factors affecting lithium metal reactivity in batteries using advanced thermal and spectroscopic techniques, aiming to improve safety and design of high-energy lithium metal batteries.

Contribution

It provides a comprehensive analysis of how electrolyte, morphology, atmosphere, and cathode materials influence lithium metal reactivity at the full cell level.

Findings

Reactivity depends on electrolyte composition and Li morphology.

Optimized conditions eliminate significant thermal reactions up to 400°C.

Reactivity varies with different cathode materials.

Abstract

Lithium (Li) metal anodes are essential for developing next-generation high-energy-density batteries. Numerous concerns on the potential safety hazards of the Li metal have been brought up before its massive application in commercialized battery packs. However, few investigations have been performed to systematically evaluate the reactivity of Li metal anode in full cell level. Here, differential scanning calorimetry (DSC) with in situ Fourier-transform infrared spectroscopy (FTIR) are used to quantitatively investigate the Li metal reactivity. Lithiated graphite (Li-Gr) and lithiated silicon (Li-Si) are also studied as the comparison samples. The reactivity of the plated Li when coupled with different electrolyte composition, morphology, and atmosphere is systematically studied. More importantly, the reactivity of Li metal full cell with different cathode materials (NMC622, LFP and LNMO) has been compared. It was found that all cell components, including electrolyte composition, Li morphology, the control of inactive Li accumulation and cathode stability, are essential in controlling the reactivity of the plated Li. After optimizing these conditions, the Li metal full cell shows no significant thermal reaction up to 400C. This work identifies the key parameters in controlling the reactivity of the plated Li and may facilitate lithium metal battery design and manufacturing in the coming future.