▎ 摘　　要

NOVELTY - Graphene-based ''lithium iron phosphate anode-silicon-oxygen composite anode'' lithium ion battery is composed of a positive electrode sheet, a negative electrode sheet, a ceramic separator, an electrolyte, and a battery shell, and after the combination of ''positive electrode sheet-ceramic diaphragm-negative electrode sheet-ceramic diaphragm'' and stacking, into the battery case, injected with electrolyte, formed into an opening, sealed, and prepared. The weight specific energy of the lithium ion battery is as high as 180 watt-hours per kilogram. The conductive agent constituting the positive/negative electrode sheet is soft carbon graphene. The positive electrode material constituting the positive electrode sheet is lithium iron phosphate with a specific capacity of 150 milliampere hour/g. The negative electrode material constituting the negative electrode sheet is a silicon-oxygen composite negative electrode with a specific capacity of 420 milliampere/g. USE - Graphene-based ''lithium iron phosphate anode-silicon-oxygen composite anode'' lithium ion battery used for power, energy storage and military industry. ADVANTAGE - The graphene-based ''lithium iron phosphate anode-silicon-oxygen composite anode'' lithium ion battery has low temperature, high rate and high energy density. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a mwthod for preparing graphene-based ''lithium iron phosphate cathode-silicon-oxygen composite anode'' lithium ion battery, whch involves: (A) making 92.5 kg of lithium iron phosphate, 2.5 kg of superconducting carbon black conductive agent, 1.5 kg of graphene conductive agent, mixed solution of 30.0 kg of macromolecular plasticizer and 3.5 kg of polyvinylidene fluoride binder into a positive electrode slurry and uniformly coating on the front and back of the nanoporous carbon-coated aluminum mesh to form a positive electrode coating; (B) reserving 20 mm blanks at the edges of the positive electrode coating plane in four directions and the edges of the nano-porous carbon-coated aluminum mesh; (C) putting in an oven and drying in a vacuum environment at 80 degrees C for 4 hours to remove the N-methylpyrrolidone solvent to obtain a positive electrode sheet; (D) using a calender to roll the positive electrode sheet to a compact state; (E) reserving the opposite side of the positive electrode tab and immerse it in the polymer glue to make it wrapped in the polymer glue, and putting the positive electrode into the oven and dry it in a vacuum environment at 110 degrees C for 4 hours to remove water to obtain a high-porosity positive electrode sheet with an areal density of 420 g/m2, a compaction density of 2.5 g/cm3, and a pole piece thickness of 0.20 mm; (F) making 35.0 kg of silicon-oxygen composite anode material, 1.36 kg of superconducting carbon black conductive agent, 0.97 kg of graphene conductive agent, 60.0 kg of macromolecular plasticizer, mixed solution of 0.97 kg of styrene butadiene rubber binder and 0.58 kg of sodium carboxymethyl cellulose binder into a negative electrode slurry and uniformly coating on the front and back of the nanoporous copper mesh to form the negative electrode coating, leaving 15 mm blanks on the edges of the negative electrode coating plane in four directions and the edges of the nanoporous copper mesh; (G) putting in an oven and drying in a vacuum environment at 80 degrees C for 4 hours to remove the water solvent and obtaining a negative electrode sheet; (H) using a calender to roll the negative electrode sheet to a compact state; (I) reserving the blank on the opposite side of the negative electrode tab on the negative electrode sheet and immersing in the polymer glue to make it wrapped by the polymer glue, and then putting the negative electrode sheet in the oven; (J) drying for 4 hours in a vacuum environment at 110 degrees C to remove water, and obtaining a high-porosity negative electrode sheet with an areal density of 165 g/m2, a compacted density of 1.6 g/cm3, and a pole piece thickness of 0.18 mm; (K) coating the front and back sides of the diaphragm with nano-alumina coatings, and removing the solvent in the alumina coating with the help of a vacuum oven to obtain nano-microstructures with high porosity and high wettability in a low temperature environment; (L) mixing ''low viscosity and low melting point solvent'', ''high viscosity and/or high melting point solvent'' and ''high capacity and high conductivity ion lithium salt-solvent combination'' to obtain high rate low temperature electrolyte; (M) laminating in the repeated sequence of ''positive sheet-ceramic separator-negative sheet-ceramic separator'', and during the stacking process, wrapping positive sheet with high-temperature insulating tape in a ''U'' shape with nanoporous carbon-coated aluminum, and reserving 20 mm blank space by the net on both sides of the positive pole ear; (N) stacking portion of the collector nanoporous carbon-coated aluminum mesh that is slightly longer than the positive electrode coating together to form multiple positive electrode tabs, and welding the multiple positive electrode tabs with the flat metal sheet current collector to form the positive electrode pole ear; (O) wrapping negative electrode sheet in a ''U'' shape with high-temperature insulating tape and the 15 mm space reserved on both sides of the negative electrode tab with the nano-porous copper mesh; and (P) compacting the dry cells to make the contact between the positive electrode sheet, the negative electrode sheet and the ceramic diaphragm more dense, and then putting the dry cells into the battery case, and connecting the positive and negative poles respectively external current collector, and after injecting electrolyte, it is made according to the conventional square battery preparation process, and obtaining a graphene-based ''lithium iron phosphate cathode-silicon-oxygen composite anode'' high-energy density lithium-ion battery with low temperature and rapid charge and discharge.