Thermal insulation phase-change hydrogel with enhanced mechanical properties for inhibiting thermal runaway propagation in lithium-ion battery module

Abstract

Thermal runaway (TR) propagation is considered to be a focal safety issue for lithium-ion batteries (LIBs) and has attracted much attention. In this work, a thermally insulating phase change hydrogel (the material) with enhanced mechanical properties was prepared to effectively inhibit the propagation of thermal runaway in LIBs. The results of microscopic morphology and elemental analysis reveal the synthesis mechanism of the thermal insulation hydrogel. The results of the mechanical property analysis show that the introduction of neopentyl glycol (NPG) and montmorillonite (MMT) increases the maximum compressive strength of the material from 15.58 MPa to 42.87 MPa, and it can effectively cope with extrusion collisions generated when triggered by TR. The thermal stability test results show that the material can absorb the heat generated when TR occurs in LIBs, and the total emission of CO and CO₂ during the heat absorption process is only 2.12 g, which is only 3.98 % of the total amount of emitted gas. The results of the thermal runaway propagation inhibition behavior study show that, compared with the blank control group, when the filler is 2 mm and 4 mm hydrogel, the TR triggering time of the adjacent heat source battery is prolonged by 294 s and 820 s, respectively, and the occurrence of TR in the diagonal battery is successfully blocked. The above results indicate that this material provides an economical, efficient, and environmentally friendly solution for suppressing TR propagation in LIBs modules.