Studies have shown that external factors that affect the capacity decay and life decay of power lithium-ion batteries include temperature, charge and discharge rate, etc., which are all determined by the user’s use conditions and actual working conditions. The following external factors that affect battery aging are the most common.
1. Depth of discharge DOD: Studies have shown that under the conditions of use of DOD (20%~80%), the increase in AC internal resistance of the battery during charging and discharging is relatively small, and deep discharge will increase the internal resistance of the battery, thereby reducing The service life of the battery. 2. Overcharge: Regardless of whether a nickel-hydrogen battery or a lithium battery, when overcharge occurs, a large amount of heat energy from the current conversion will be emitted, leading to numerous reactions inside the battery. 3. Self-discharge: Li-ion power batteries will self-discharge. Usually self-discharge shows the loss of battery capacity. Most self-discharge is reversible, but there is still irreversible self-discharge. 4. Ambient temperature: Too low temperature will affect the activity of the electrolyte inside the battery, which will reduce the battery’s charge and discharge efficiency. Too high temperature will destroy the chemical balance system inside the battery, and the battery will also occur at high temperatures. Many irreversible side reactions deform the electrode structure of the battery, reduce the battery capacity, and also reduce the number of battery cycles. 5. Pressure: In order to facilitate the diffusion of lithium ions inside the battery, the diaphragm and the positive and negative electrodes of the lithium battery usually have a porous structure, and the pressure will have a certain effect on the porosity and tortuosity of the porous material, so the mechanical pressure will indirectly affect The diffusion rate of lithium ions between the positive and negative electrodes and the separator affects the discharge performance of the lithium battery. Therefore, it is necessary to study the battery pressure.
Post time: Nov-09-2021