▎ 摘　　要

NOVELTY - Low-temperature lithium iron phosphate lithium-ion power battery comprises a positive electrode sheet, a negative electrode sheet, a diaphragm, an electrolyte, and a battery shell column, where the positive electrode material in the positive electrode sheet comprises a positive electrode active material, a binder, a conductive agent and a positive electrode current collector, where the positive electrode active material is made of carbon-coated lithium iron phosphate material, the binder uses polyvinylidene fluoride, the conductive agent uses conductive carbon black, conductive graphite, flake graphite, and/or carbon nanotubes, the current collector is aluminum foil, the negative electrode material in the negative electrode sheet comprises negative electrode active material, conductive agent, thickening agent, binder and negative electrode current collector, and the negative electrode active material is middle layer graphite and carbon-coated graphite. USE - As low-temperature lithium iron phosphate lithium-ion power battery. ADVANTAGE - The low-temperature lithium iron phosphate lithium ion power battery has excellent electrochemical performance, cycle stability and cycle characteristics, and reduced generation of electrolyte decomposition product on the surface of the battery anode. DETAILED DESCRIPTION - Low-temperature lithium iron phosphate lithium-ion power battery comprises a positive electrode sheet, a negative electrode sheet, a diaphragm, an electrolyte, and a battery shell column, where the positive electrode material in the positive electrode sheet comprises a positive electrode active material, a binder, a conductive agent and a positive electrode current collector, where the positive electrode active material is made of carbon-coated lithium iron phosphate material, the thickness of the nano-carbon layer in carbon-coated lithium iron phosphate is 2-5 nm thick, the carbon-coated lithium iron phosphate is prepared by taking bis-1,6-hexylidene triamine pentamethylene phosphonic acid, ferrous carbonate and lithium hydroxide and dissolving in deionized water, adding graphene, in which the dosage of graphene is half the amount of lithium hydroxide, magnetically stirring until dissolved, transferring the solution to a stainless steel reaction kettle, reacting at 175-185degrees Celsius for 5-7 hours, cooling, washing, performing suction filtration, vacuum-drying under conditions to obtain precursor powder, placing the precursor powder in a tubular furnace, heating at 700degrees Celsius under the protection of high-purity argon gas, and heat-preserving for 120 minutes, the binder uses polyvinylidene fluoride, the conductive agent uses conductive carbon black, conductive graphite, flake graphite, and/or carbon nanotubes, the current collector is aluminum foil, the dosage ratio of the conductive agent is (82-93):(2-8):(6-12), the negative electrode material in the negative electrode sheet comprises negative electrode active material, conductive agent, thickening agent, binder and negative electrode current collector, and the negative electrode active material is middle layer graphite and carbon-coated graphite at a ratio of (1.3-3.5):(4.2-5.6), the conductive agent comprises conductive carbon black, conductive graphite, graphene and/or graphene slurry, the thickening agent is sodium carboxymethyl cellulose, the binder is styrene-butadiene rubber, the current collector is copper foil, the dosage ratio of negative electrode active material, conductive agent, thickening agent and binder is (89-96):(2-5):(2-7):(1-6), and the electrolyte is prepared by adding methyl methacrylate, methyl eicosate and butyl acrylate in a glove box filled with argon gas, and adding lithium salts lithium hexafluorophosphate and lithium tetrafluorophosphate to make the concentration of lithium salts to 1-1.2 mol/l to obtain the electrolyte. An INDEPENDENT CLAIM is also included for a low-temperature discharge method for the power battery, which involves (i) adopting a battery management system to detect the temperature of the battery in real time, and (ii) reading the preset rules by the battery management system, and when the temperature is lower than -10degrees Celsius, and activating a temperature compensation device to increase the temperature of the power battery.