Lithium iron phosphate battery is a lithium-ion battery using lithium iron phosphate (LiFePO4) as the cathode material, carbon as the cathode material, the single rated voltage of 3.2 V, the charge cut-off voltage of 3.6 V ~ 3.65 V. It is currently the most environmentally friendly of all lithium battery pack, the highest life expectancy, the highest safety, the largest discharge rate.
First, the working principle of lithium iron phosphate batteries
Lithium iron phosphate battery in charging, the positive electrode of lithium ion Li + through the polymer diaphragm to the negative electrode migration; in the discharge process, the negative electrode of lithium ion Li + through the diaphragm to the positive electrode migration. Lithium-ion batteries are named for the lithium ions migrating back and forth during charging and discharging.
1, lithium iron phosphate battery charging, Li + from the 010 surface of lithium iron phosphate crystal migration to the surface of the crystal, under the action of electric field forces, into the electrolyte, through the diaphragm, and then by electrolysis migrate to the surface of graphene, and then embedded in the graphene lattice, at the same time, electrons flow through the conductive body to the positive aluminum foil electrode, through the pole lug, battery pole column, external circuit, negative pole column, negative pole lug flow to the negative copper foil collector, and then through the conductive body to the negative graphite electrode, is the negative charge to equilibrium, lithium ions from lithium iron phosphate deembedded, lithium iron phosphate into iron phosphate.
2, lithium iron phosphate battery discharge, Li + deembedded from the graphite crystal, into the electrolyte, through the diaphragm, and then migrate through the electrolyte to the surface of the lithium iron phosphate crystal, and then re-embedded in the lattice of lithium iron phosphate by 010 surface. At the same time, the cell flows through the conductive body to the copper foil collector of the negative electrode, through the pole lug, the negative pole post of the cell, the external circuit, the positive pole post, the positive pole lug to the copper foil collector of the positive electrode, and then through the conductive body to the positive electrode of lithium iron phosphate, so that the charge of the positive electrode reaches a balanced state.
Second, the lithium iron phosphate battery group chemical reaction equation
Positive electrode reaction: LiFePO4?Li1-xFePO4+xLi++xe-.
Negative electrode reaction: xLi++xe-+6C?LixC6.
Total reaction formula: LiFePO4+6xC?Li1-xFePO4+LixC6.
The above is the introduction of the working principle and chemical reaction equation of lithium iron phosphate batteries. Lithium iron phosphate battery has a high operating voltage, high energy density, long cycle life, small self-discharge rate, no memory effect, green and a series of unique advantages, and support stepless expansion, suitable for large-scale electrical energy storage, in renewable energy power station power generation safety to the grid, grid peaking, distributed power stations, UPS power supply, emergency power systems and other fields have good prospects for application.
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