Rechargeable battery, also known as accumulators, refer to the use of two substances as positive and negative electrodes and a specific non-aqueous solution as electrolyte to form a recyclable battery, that is, after the battery is discharged, the internal active material is activated by charging and can be recycled. Battery.
The new battery is assembled through the reversible process of chemical reaction, that is, after the chemical reaction reaches the electrical energy state, the electrical energy can be converted back to the chemical system to return it to the original state, and then the chemical reaction is converted into electrical energy. Series, so called rechargeable batteries.
For dry batteries, the charge and discharge cycles of rechargeable batteries can be divided into many types, ranging from thousands to tens of thousands of times, so rechargeable batteries are cost-effective.
The self-discharge of a rechargeable battery is also called the charge retention capability, which refers to the capacity of the battery to maintain the charge state after storage under certain conditions in an open circuit state. Mainly affected by storage conditions, manufacturing processes, and materials, it is one of the main parameters to measure battery performance. Generally speaking, the battery storage temperature is directly proportional to the self-discharge rate. The battery storage temperature is high, and the self-discharge rate is high; the battery storage temperature is low, and the self-discharge rate is low. But you should also pay attention to the temperature not to be too low or too high, too high or too low may damage the battery and cause it to be unusable. The storage temperature range of -20~45 is required by BYD conventional batteries. After a fully charged battery is left open for a period of time, a certain degree of self-discharge is normal. The IEC standard stipulates that after nickel-cadmium and nickel-hydrogen batteries are fully charged, at a temperature of 20 degrees and a humidity of 65%, they are left open for 28 days, and the discharge time of 0.2C is greater than 3 hours and 3 hours and 15 minutes respectively.
Compared with other rechargeable battery systems, solar cells containing liquid electrolyte have a much lower self-discharge rate. At a temperature of 25 degrees, the self-discharge rate is about 10%/month.
Secondary battery charge and discharge equation
Writing method. Pb+PbO2+2H2SO4==discharge==2PbSO4+2H2O
①The negative electrode loses electrons. Find the Pb lost electrons from the equation to become PbSO4 (cannot be disassembled) and write Pb-e-=PbSO4
②Find the loss 2e- according to the valence: write Pb-2e-=PbSO4
③According to the law of conservation of elements, the left side lacks SO42-; write Pb-2e-+SO42—=PbSO4 then the charge in this equation is also conserved. (If it does not conform to the law of conservation, you can add H+ or OH-)