Liquid cooling for battery energy storage: what the standards actually regulate

Liquid cooling exists in a battery energy storage system for two reasons: to keep every cell inside its recommended temperature window, and to keep cell-to-cell temperature spread small enough that the pack ages evenly. Indirect (cold-plate) designs dominate stationary storage, and inhibited glycol-water fluids are the usual carrier because of their heat capacity and low-temperature behaviour.

GB 38031-2020 regulates system-level safety behaviour: after thermal runaway is triggered in a single cell, the battery pack must not fire or explode within five minutes, giving occupants or operators an evacuation window. The cooling loop is part of that mitigation story, but the standard regulates the outcome, not the coolant chemistry.

GB/T 36276-2018 sets requirements and test methods for power-storage lithium-ion batteries (performance, safety, cycle life), while GB/T 42288-2022 sets station-level safety regulations covering design, fire protection and operation. Neither prescribes a coolant formulation; coolant quality enters these frames through material compatibility and long-term stability of the loop.

So what should a buyer require from the coolant supplier? Corrosion protection for aluminium, copper and solder (ask for reserved corrosion-test data), elastomer compatibility for EPDM and NBR seals, pH and reserve-alkaline stability for glycol-based fluids, and — for any direct-contact design — dielectric properties and moisture control.

Documentation should follow each batch: a certificate of analysis with measured pH, reserve alkalinity, density and freeze point; a GHS-format safety data sheet; and clear guidance on storage and on dilution with deionised water only. Batch-traceable paperwork is what turns a good fluid into a defensible engineering choice.