Meaning
Electrochemical transport processes govern the movement of lithium ions through the liquid medium separating the positive and negative electrodes of a cell. The rate of electrolyte lithium ion diffusion limits how quickly a battery can be charged or discharged without causing lithium plating on the anode. This transport rate is a fundamental characteristic of cell chemistry that dictates the safe limits of fast-charging algorithms and defines the boundary where rapid energy storage begins to degrade the structural integrity of the electrode material.
Transport Mechanism
Concentration gradients drive the ions through the porous polymer separator during cell operation. The ions must move freely through the liquid filled pores of the separator to maintain the electrochemical reaction. This flow rate determines the internal resistance of the battery.
Temperature Dependence
Cold environments increase the viscosity of the liquid solvent, which slows down the transport process. This slow-down reduces the available capacity and can trigger voltage drops under high load. Heating jackets are sometimes added to maintain the cell temperature.
Cell Performance
High-drain tasks like wireless transmission require cells designed with high-diffusion electrolyte formulations to avoid voltage drops. These specialized cells use low-viscosity solvents and thin separators to maximize the ion flux during short bursts of high current draw.
