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.