Charging methods for lithium-ion batteries
Method 1: Before leaving the factory, the lithium-ion battery is activated and pre charged by the manufacturer. Therefore, the lithium-ion battery has excess charge. The lithium-ion battery is charged according to the adjustment period, which requires 3-5 complete charges and discharges.
Method 2: Before charging, do not specifically discharge the lithium-ion battery, as improper discharge can damage the battery. When charging, try to charge slowly and reduce fast charging methods; Do not exceed 24 hours. The battery undergoes three to five complete charge and discharge cycles before all internal chemicals are activated to achieve optimal usage.
Method 3: Please use a charger from the original factory or a reputable brand. For lithium-ion batteries, use a dedicated charger for lithium-ion batteries and follow the instructions, otherwise the battery may be damaged or even dangerous.
Method 4: If the newly purchased battery is lithium-ion, the first 3-5 charges are generally referred to as the adjustment period, and should be charged for more than 14 hours to ensure full activation of lithium-ion activity. Lithium ion batteries do not have memory effects, but they have strong durability and should be fully activated to ensure optimal performance for future use.
Method 5: Lithium ion batteries must use a dedicated charger, otherwise they may not reach saturation state and affect their performance. After charging, it should be prevented from being placed on the charger for more than 12 hours. When not in use for a long time, the battery and mobile electronic products should be separated.
Charging process of lithium-ion batteries
Lithium ion batteries are a type of secondary battery (rechargeable battery) that relies heavily on the movement of lithium ions between the positive and negative electrodes for operation. During the charging and discharging process, Li+is intercalated and disembedded back and forth between the two electrodes: during charging, Li+is disembedded from the positive electrode, embedded into the negative electrode through the electrolyte, and the negative electrode is in a lithium rich state; When discharging, the opposite is true.
Lithium ion batteries are known as rocking chair batteries, where charged ions move between the positive and negative electrodes, achieving charge transfer and supplying power to external circuits or charging from external sources. During the specific charging process, an external voltage is applied to the two poles of the battery, and lithium ions detach from the positive electrode material and enter the electrolyte. At the same time, excess electrons pass through the positive electrode collector and move towards the negative electrode through the external circuit; Lithium ions move from the positive electrode to the negative electrode in the electrolyte, passing through the separator and reaching the negative electrode; The SEI film on the surface of the negative electrode is embedded into the layered structure of the negative electrode graphite and combines with electrons.
The most suitable charging process for lithium-ion batteries can be divided into four stages: trickle charging, constant current charging, constant voltage charging, and charging termination.
Stage 1: Trickle charging Trickle charging is used to pre charge (restorative charging) the fully discharged battery unit first. When the battery voltage is below about 3V, first charge the battery with a constant current of up to 0.1C.
Stage 2: Constant Current Charging: When the battery voltage rises above the trickle charging threshold, increase the charging current for constant current charging. The current for constant current charging is between 0.2C and 1.0C. The current during constant current charging is not required to be very accurate, and quasi constant current can also be used. In linear charger design, the current often increases with the increase of battery voltage to minimize heat dissipation issues on the transmission transistor.
Stage 3: Constant voltage charging: When the battery voltage rises to 4.2V, constant current charging ends and the constant voltage charging phase begins. To achieve optimal performance, the voltage stabilization tolerance should be better than+1%.
Stage 4: Charging termination is different from nickel batteries, and continuous trickle charging of lithium-ion batteries is not recommended. Continuous trickle charging can cause electrode plating effects on metallic lithium. This will make the battery unstable and may lead to sudden automatic rapid disassembly.