What Is Battery Corrosion?

Understanding Battery Corrosion

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Battery corrosion is a multifaceted problem that varies across different battery technologies. Understanding the specific corrosion mechanisms and their influencing factors is crucial for developing strategies to enhance battery performance and longevity. Advances in electrolyte formulations and protective coatings offer promising solutions to mitigate corrosion and improve the reliability of batteries in various applications.

Battery corrosion is a critical issue affecting the performance and longevity of various types of batteries. It involves the degradation of battery components due to chemical reactions, often leading to reduced efficiency, capacity loss, and even failure. This article explores the mechanisms and impacts of battery corrosion across different battery technologies.

Lead-Acid Battery Corrosion

In lead-acid batteries, corrosion primarily affects the grids, plate-lugs, straps, or posts, leading to a gradual loss of performance and eventually the end of service life. Anodic corrosion is a significant aging process, often exacerbated by overcharging, which accelerates both corrosion and water loss. The corrosion of grids increases resistance to current flow, impeding proper charging and resulting in sulfation. Temperature and acid concentration also influence corrosion rates, with higher temperatures accelerating corrosion and water loss1.

Aluminum Corrosion in Sodium-Ion and Lithium-Ion Batteries

Aluminum corrosion is a notable issue in sodium-ion and lithium-ion batteries, particularly affecting the current collectors. In sodium-ion batteries, the use of ionic liquid electrolytes can suppress but not entirely prevent aluminum corrosion, which is influenced by temperature and salt concentration. High temperatures and low salt concentrations exacerbate corrosion, affecting battery stability and capacity2. Similarly, in lithium-ion batteries, aluminum corrosion is triggered by the electrochemical oxidation of solvent molecules at high potentials, leading to the dissolution of aluminum ions and impacting battery performance7 10.

Corrosion in Alkaline and Si-Air Batteries

In alkaline batteries, steel corrosion can lead to internal shorting and gassing, undermining battery reliability. The corrosion behavior varies with temperature, with nickel showing spontaneous passivation, while iron and cobalt exhibit different passivation behaviors5. In Si-air batteries, high corrosion rates significantly reduce the theoretical capacity, with corrosion being influenced by electrolyte concentration and discharge conditions6.

Mitigating Corrosion

Efforts to mitigate corrosion include the use of protective coatings, modification of surface chemistry, and the development of concentrated electrolytes. For instance, in lithium metal batteries, polymer coatings and surface modifications help stabilize the lithium metal surface, reducing corrosion rates4. In high-voltage lithium metal batteries, high-concentration electrolytes have been shown to mitigate aluminum corrosion, enhancing long-term stability8.