Desiccant for Electrochemical Energy Storage

Electrochemical (e.g., Lithium-ion, Sodium-ion) energy storage systems are extremely sensitive to humidity. Moisture ingress is one of the core factors leading to performance degradation and safety risks. Energy storage battery cells, packs, and clusters are all high-value products. Significant losses can occur once they are exposed to moisture. Core Hazards of Moisture Ingress Electrochemical Performance Degradation: Side Reactions and Corrosion: Water reacts with lithium salts (e.g., LiPF₆) in the electrolyte to generate corrosive acids (e.g., HF). This corrodes active materials in the cathode and anode, depletes available lithium ions, and leads to irreversible capacity loss. Gas Generation and Swelling: Side reactions produce gases, causing increased internal pressure and swelling within the cell/battery pack. In severe cases, this can lead to casing deformation or activation of the vent. Increased Internal Resistance: Corrosion products and interface deterioration raise internal resistance, impairing charge/discharge efficiency and power performance while exacerbating heat generation. Significantly Increased Safety Risks: Internal Short Circuit Risk: A humid environment can cause localized wetting of the separator or corrosion of metal components leading to lithium plating, thereby increasing the probability of short circuits. Thermal Runaway Trigger: Moisture-compromised cells exhibit reduced thermal stability during charging, discharging, or under abnormal conditions, lowering the threshold for triggering thermal runaway. Physical Corrosion and Insulation Failure (Particularly Critical at the Battery Pack and System Level): Electrical Connection Corrosion: Moisture-induced oxidation of high-voltage connectors, such as busbars and terminals, increases contact resistance. This leads to localized overheating, energy loss, and potential connection failure. BMS and PCS Component Failure: Moisture exposure to circuit boards and components in control units like the Battery Management System (BMS) and Power Conversion System (PCS) can cause pin corrosion, signal drift, and malfunction or failure of protection features. Reduced Insulation Performance: After absorbing moisture, internal insulation materials (e.g., films, epoxy boards) experience a significant drop in insulation resistance. This can lead to high-voltage component leakage to ground, insulation alarms, or the creation of unintended conductive paths.