Meaning
Current extraction from battery cells at reduced temperatures is subject to kinetic limitations. This cold-weather performance metric, called low temperature discharge, describes the cell’s ability to release stored energy below zero degrees Celsius. It is constrained by the slowdown of electrochemical reactions in the electrodes.
Kinetic Limitation
Electrolyte viscosity increases as the temperature falls, which slows down the transport of lithium ions between the anode and cathode. During low temperature discharge, this slow diffusion leads to increased internal resistance and reduced active capacity. This effect is temporary and reverses once the battery warms up.
Voltage Behavior
Extreme polarization causes the cell voltage to drop rapidly during the initial stage of current extraction. When low temperature discharge occurs, the terminal voltage may drop below the cutoff threshold prematurely, triggering the battery management system to shut down. This behavior is mitigated by optimizing the electrolyte composition with low-viscosity co-solvents that preserve ion transport at sub-zero levels, which helps sustain the discharge plateaus required by high-power applications.
Sourcing Parameter
Energy storage system buyers evaluate cold-weather performance to select cells for outdoor installations. Specifying low temperature discharge capabilities ensures that the system will meet local grid demands in winter. This parameter helps prevent unexpected system shutdown in northern regions.
