Flowerlike CeO₂ used as novel adsorption material for removal of hydrogen fluoride gas from lithium-ion battery during thermal runaway

Abstract

Thermal runaway presents a significant challenge for large-scale application of lithium-ion batteries (LIBs), often leading to the release of flammable, explosive, and toxic gases. In this study, porous flowerlike cerium dioxide microspheres (FL-CeO₂) were investigated to eliminate hydrogen fluoride (HF) gas generated during thermal runaway. A dedicated test device and method were developed for this purpose. The FL-CeO₂ was synthesized via a hydrothermal method and coated onto nickel foam to fabricate a gas filter. During thermal runaway of a 5 Ah lithium iron phosphate (LiFePO₄) battery, the filter—loaded with 1.2 g CeO₂—achieved an instantaneous HF removal rate of up to 82.24% within approximately 40–50 s. X-ray photoelectron spectroscopy (XPS) results indicate that F⁻ ions replace O²⁻ ions in the CeO₂ lattice. Additionally, the potential for reusability of the CeO₂ microspheres was evaluated through multiple HF adsorption and desorption cycles. After 10 cycles, the regenerated CeO₂ microspheres retained a HF adsorption rate of 76.11%, demonstrating promising reusability.

Graphical abstract

Keywords

lithium-ion batteries (LIBs) / thermal runaway / ceria microspheres / hydrogen fluoride (HF) / regeneration

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Higher Education Press 2025