▎ 摘　　要

NOVELTY - Composite phosphate positive electrode material comprises lithium iron manganese potassium phosphate composite. USE - Composite phosphate positive electrode material used in new energy transportation power battery market, consumer battery market and energy storage battery market. ADVANTAGE - The composite phosphate positive electrode material uses fast ion conductor Q, intermetallic compound G and carbon material conductor C to modify the composite phosphate cathode material, improves the ionic conductivity and electronic conductivity of the material, have a higher voltage platform and energy density, and have superior low temperature performance. The preparation method is simple, easy to large-scale production, and low material cost. DETAILED DESCRIPTION - Composite phosphate positive electrode material, comprises lithium iron manganese potassium phosphate composite of formula, i.e. aLi1 + xFe1-x-y-z-kMnyM1zM2kPO4F-bQ.cG.dC, where x=0-0.1;y=0-0.9;z=0 0.2;k=0-0.2;a=70-100 %;b=0-10%;c=0-10%;d=0.5-5%;a+b+c+d=1;M1, M2=doping element;F=cosolvent;Q=fast ionic conductor;G=intermetallic compound; and C=carbon material conductor. An INDEPENDENT CLAIM is included for a method for preparing composite phosphate positive electrode material, which involves: preparing mixed liquid L1 containing iron source, manganese source, optionally M1 source and M2 source; preparing mixed liquid L2 containing phosphorus source and ammonia source; preparing a solution L3 containing an active agent; preparing the acidity-basicity regulator ammonia water L4; the L1, L2, L3 solution is gradually injected into the protection of reaction vessel gas, controlling at 45-90℃ in the reaction process, the stirring speed is 90-150 revolution per minute, then gradually injecting the L4 solution to adjust the pH value, the pH value is controlled at 4.0-7.0, the reaction time is 30-100 minutes, preferably the reaction temperature is 75-85℃, the stirring speed is 100-120 revolution per minute, the pH value is controlled at 5.0-6.5, the reaction time is 50-80 minutes; carrying out solid-liquid separation for the slurry obtained by precipitation reaction, then washing for 3-5 times by using deionized water; drying and dehydrating the powder at 100-250℃ for 3-8 hours to obtain the precursor Fe1-y-z-kMnyM1zM2kHPO4 of crystal composite phosphate positive electrode material with orthogonal crystal system, the average granularity is 0.3-5.0 microns, preferably 0.4-1.0 microns, the ratio of raw material 1: the lithium source, precursor and fluoride is 1.0-1.1: 0.9-1.0: 0.01-0.1: weighing the carbon source, obtaining the carbon material conductor, the dosage of the carbon source makes the content of the carbon in the composite phosphate positive electrode product is 0.5-5 wt.% according to the mass to obtain the semi-finished product W1; putting the semi-finished product W1 into the breaking and mixing device, then adding a certain amount of dispersant and crushing medium into the device, crushing the material to nanometer level and homogeneous mixing, drying to obtain the semifinished product W2; putting the W2 into the sintering boat, sending into the atmosphere crystallization synthesis furnace containing protective gas, decomposing at the temperature of 2000 degrees centigrade to 500℃, carbonizing for 2-5 hours, then raising the temperature to 600- 850℃, crystallizing and synthesizing and compounding for 5-15 hours, then reducing the temperature to room temperature, crushing and sieving to obtain the composite phosphate lithium the positive electrode material aLi1 + xFe1-x-y-zkMnyM1zM2kPO4F-bQ-cG-dC.