Chemically Self-Powered Pre-Activation Strategy for Catalytic Purification of Lithium-Ion Battery Thermal Runaway Off-Gas

Abstract

During lithium-ion battery thermal runaway, oxygen-depleted, highly concentrated flammable fumes are released, posing a significant challenge to safety control. Catalytic oxidation requires both sufficient O₂ and elevated temperatures for activation. However, thermal runaway off-gas is inherently oxygen-free, creating a fundamental paradox: direct air supply cools the gas below activation threshold, while pre-heating demands external energy input. To address this issue, this study proposes a chemically self-powered pre-activation strategy based on both O₂ and heat supply. By placing superoxides upstream of the catalyst and utilising their exothermic reaction with CO₂ in the fumes, the necessary O₂ and reaction heat were released during the initial stage of catalytic oxidation. Simultaneously, a blower is introduced to provide a continuous O₂ supply for subsequent sustained oxidation. This strategy achieves purification efficiencies exceeding 87% for both H₂ and CO throughout the thermal runaway event with zero open flame occurrence and outlet temperatures below 100°C, ensuring safe discharge. This study provides a viable technical pathway for the post-treatment of battery thermal runaway emissions, eliminating dependency on external heating or compressed oxygen supplies.