The charging and discharging reactions of lithium iron phosphate batteries occur between LiFePO4 and FePO4 phases. During the charging process, LiFePO4 gradually separates from lithium ions to form FePO4. During the discharge process, lithium ions are embedded in FePO4 to form LiFePO4.
When the battery is charged, lithium ions migrate from the lithium iron phosphate crystal to the surface of the crystal, enter the electrolyte under the action of electric field force, pass through the separator, and then migrate to the surface of the graphite crystal through the electrolyte, and then embed into the graphite lattice.
At the same time, electrons flow through the conductive body to the aluminum foil collector of the positive electrode, through the electrode ear, battery positive pole, external circuit, negative pole pole, and negative pole ear to the copper foil collector of the negative electrode of the battery, and then through the conductive body to the graphite negative electrode, causing the charge of the negative electrode to reach equilibrium. After lithium ions are deintercaled from lithium iron phosphate, lithium iron phosphate is converted into iron phosphate.
When the battery is discharged, lithium ions detach from graphite crystals, enter the electrolyte, pass through the separator, migrate to the surface of lithium iron phosphate crystals through the electrolyte, and then re embed into the lattice of lithium iron phosphate.
At the same time, electrons flow through the conductive body to the copper foil collector of the negative electrode, through the electrode ear, battery negative pole, external circuit, positive pole pole, and positive pole ear to the aluminum foil collector of the battery positive electrode, and then through the conductive body to the lithium iron phosphate positive electrode, causing the charge of the positive electrode to reach equilibrium. After lithium ions are embedded into iron phosphate crystals, iron phosphate is converted into lithium iron phosphate.
