1. Charging of ternary lithium-ion battery
The maximum charge termination voltage of a single-cell lithium-ion battery is 4.2V, and it cannot be overcharged, otherwise the battery will be scrapped due to the loss of too much lithium ions in the positive electrode. When charging the lithium-ion battery, a dedicated constant-current and constant-voltage charger should be used. First, the constant-current charge until the voltage at both ends of the lithium-ion battery is 4.2V, and then switch to the constant-voltage charging mode; when the constant-voltage charging current drops to 100mA should stop charging.
The charging current (mA) can be 0.1 to 1.5 times the battery capacity. For example, for a 1350mAh lithium-ion battery, the charging current can be controlled between 135mA and 2025mA. The conventional charging current can be selected at about 0.5 times the battery capacity, and the charging time is about 2 to 3 hours.
2. Discharge of ternary lithium-ion battery
Due to the internal structure of the lithium-ion battery, the lithium ions cannot all move to the positive electrode during discharge, and a part of the lithium ions must be retained at the negative electrode to ensure that the lithium ions can be smoothly inserted into the channel during the next charging. Otherwise, battery life will be shortened. In order to ensure that some lithium ions remain in the graphite layer after discharge, it is necessary to strictly limit the minimum discharge termination voltage, that is to say, the lithium ion battery cannot be overdischarged. The discharge termination voltage of a single-cell lithium-ion battery is usually 3.0V, and the minimum cannot be lower than 2.5V. The length of battery discharge time is related to battery capacity and discharge current. Battery discharge time (hours) = battery capacity/discharge current, and the lithium-ion battery discharge current (mA) should not exceed 3 times the battery capacity, for example: 1000mAh lithium-ion battery, the discharge current should be strictly controlled within 3A, otherwise will damage the battery.
It is not difficult to see that during the charging and discharging process of the lithium ion battery, the lithium ions are in a state of movement from the positive electrode → negative electrode → positive electrode. If we compare the lithium-ion battery to a rocking chair, the two ends of the rocking chair are the poles of the battery, and the lithium ion is like an excellent sportsman, running back and forth between the two ends of the rocking chair. So, experts have given lithium-ion batteries another cute name, rocking chair batteries.
