Effects of Salt Spray Corrosion on Thermal Runaway of Lithium-ion Batteries

The increasing electrification of marine equipment underscores the need to ensure lithium-ion battery (LIB) safety in corrosive environments. Unlike land applications, shipboard batteries are continuously exposed to salt spray, which accelerates material degradation and raises the risk of thermal hazards. Thus, this study investigates the effects of salt spray corrosion on the electrochemical performance and Thermal runaway (TR) behavior of commercial 18650-type ternary LIBs. Through charge-discharge calorimetry and cone calorimeter tests, variations in voltage response, capacity fade, mass loss, and heat release rate were analyzed under different states of charge (SOC), states of health (SOH), and exposure durations. The results show that corrosion significantly accelerates electrode deterioration, leading to faster capacity decline and voltage plateau shifts. At higher SOH, casing rupture induced earlier TR with violent combustion, whereas at lower SOH, corrosion-induced energy depletion delayed onset and reduced flame intensity. Mass loss increased with decreasing SOH, while the effective heat of combustion remained relatively stable. Thus, salt spray intrusion can cause damage to the internal structure of the battery, inhibit electrochemical reactions, and significantly reduce the operational function, thereby bringing potential safety risks.