Lithium nickel manganese oxygen composite cathode material and preparation method thereof

[0037] Example 1

[0038] 1. Weigh 13.142g NiSO respectively 4 ·6H 2 O and 25.35gMnSO 4 ·H 2 O is prepared into a mixed aqueous solution. Under stirring, NaOH solution is added dropwise to the mixed solution, and the pH value of the mixed solution is controlled at about 10.3 to ensure Ni 2 +, Mn 2+ The precipitation is complete, after standing for 2 hours, suction filtration, washing three times, and drying at 110°C for 12 hours to obtain 17.85g Ni 0.5 Mn 1.5 (OH) 4 , Respectively weigh 3.6gNi 0.5 Mn 1.5 (OH) 4 And 0.739gLi 2 CO 3 , Ball milling to mix uniformly, then program temperature controlled air atmosphere sintering, heating to 500°C at a heating rate of 4°C/min, holding for 4 hours; then heating to 900°C at a heating rate of 5°C/min, calcination for 10 hours; then cooling at 5°C/min The speed drops to 600℃, annealing for 12h; finally, the temperature is naturally cooled to room temperature. Get 3.52g LiNi 0.5 Mn 1.5 O 4.

[0039] 2. Weigh 6gLiNi separately 0.5 Mn 1.5 O 4 , 0.061g carbon black, 0.245g sucrose were added to the planetary ball mill, ball milled at a speed of 400r/min for 4 hours, mixed uniformly, sintered in an air atmosphere, heated at a rate of 4°C/min to 400°C, kept for 1 hour to make the carbon source The precursor is carbonized to obtain a lithium nickel manganese oxygen composite cathode material.

[0040] 3. Put LiNi 0.5 Mn 1.5 O 4 And its composite materials were mixed with the conductive agent acetylene black and the binder PVDF (polyvinylidene fluoride) at a mass ratio of 8:1:1, and the mixture was prepared into a slurry with NMP (1-methyl-2-pyrrolidone) Coat the aluminum foil evenly, put it in an oven, dry at 80-120°C for 1 hour, take out the punched pole piece, vacuum dry at 85°C for 12 hours, press the tablet, vacuum dry at 85°C for 12 hours, to make an experimental battery Use pole pieces. Use lithium sheet as counter electrode, electrolyte is 1.5mol/L LiPF 6 EC (ethyl carbonate) + DMC (dimethyl carbonate) (volume ratio 1:1) solution, the diaphragm is celgard2400 membrane, assembled into a CR2025 button cell in a glove box filled with argon atmosphere, charge and discharge The cut-off voltage is 3.5~4.9V, the charge and discharge cycle setting: the first to fifth charge and discharge current is 0.1C, the sixth to tenth charge and discharge current is 0.2C, the 11th to 100th charge and discharge current is 1C (1C= 130mA/g).

[0041] Example 2

[0042] 1. Preparation of LiNi 0.5 Mn 1.5 O 4 The scheme is the same as in Example 1

[0043] 2. Weigh 5gLiNi separately 0.5 Mn 1.5 O 4 , 0.048g acetylene black and 2.31g sucrose are added to the planetary ball mill, ball milled at 500r/min for 3h, the ball mill is evenly mixed, and sintered in an air atmosphere. The temperature rise rate is 5°C/min to 400°C, and the temperature is kept for 1.5 hours. The precursor body is carbonized to obtain lithium nickel manganese oxygen composite cathode material.

[0044] 3. The test methods of the composite cathode material assembled battery are the same as in Example 1

[0045] Example 3

[0046] 1. Preparation of LiNi 0.5 Mn 1.5 O 4 The scheme is the same as in Example 1

[0047] 2. Weigh 8gLiNi separately 0.5 Mn 1.5 O 4 , 0.081g Super P, 0.472g polyvinyl alcohol were added to the planetary ball mill, ball milled at a speed of 350r/min for 7 hours, the ball mill was mixed uniformly, and sintered in an air atmosphere. The temperature was increased at a rate of 6°C/min to 500°C and kept for 1.5 hours. The precursor of the carbon source is carbonized to obtain lithium nickel manganese oxygen composite cathode material.

[0048] 3. The test methods of the composite cathode material assembled battery are the same as in Example 1