The process of charging and discharging a capacitor
(1) The process of charging.
The process of charging a capacitor (storing charge and energy) is called charging. Connect one pole plate of the capacitor to the positive pole of the power supply, and the other pole plate to the negative pole of the power supply, and the two pole plates are respectively charged with the same amount of different charges. After charging, there is an electric field between the two plates of the capacitor, and the charging process stores the electric energy obtained from the power supply in the capacitor.
(2) The process of discharging.
The process of causing a charged capacitor to lose its charge (release charge and energy) is called discharging. For example, connect the two poles of the capacitor with a wire, and the charges on the two poles will neutralize each other, and the capacitor will release electric charge and electric energy. After discharge, the electric field between the two plates of the capacitor disappears, and the electrical energy is converted into other forms of energy.
Battery self-discharge refers to the ability of a battery to maintain a stored charge in an open circuit condition. The self-discharge types of lithium-ion batteries can be divided into physical self-discharge and chemical self-discharge. The battery cells are connected in series and parallel to form a module. If the self-discharge consistency of the cells in the module is poor, it will lead to inconsistent voltages at the internal cell terminals after the module has been stored for a period of time. As a result, during the charging and discharging process of the module, some monomers have reached the target voltage, while other monomers are still at a higher or lower voltage, resulting in overcharging or overdischarging of the monomers, and even safety problems. This is also a challenge to the voltage equalization capability of the module. Self-discharge is an important performance indicator of lithium-ion capacitors.
