Glassy carbon electrode made from nano-sized magnesium oxide has many characteristics, such as good battery stability, high conductivity, high purity, no gas in the electrode, easy surface regeneration, low overpotential of hydrogen and oxygen, cheap, etc. However, these are more general statements, so what is the specific role of magnesium oxide in lithium batteries?
First of all, insoluble solid particles such as TiO2, SiO2, Cr2O3, ZrO2, CeO2, Fe2O3, Baso, SiC, MgO and so on were selected to add 10-100g/L of TiO2, SiO2, Cr2O3, ZrO2, CeO2, Fe2O3, Baso, SiC and MgO to lithium-ion battery with diameter of 0.05-10μm. The material made as lithium ion has the characteristics of good charging and discharging efficiency, high specific capacity and stable cycling performance.
Secondly, the cathode material of lithium battery, using nano-sized magnesium oxide as conductive dopant, generates Mg-doped lithium, iron, manganese phosphate through solid phase reaction, and further makes the nano-structured cathode material, whose actual discharge capacity reaches 240mAh/g. The new cathode material has the characteristics of high energy, safety and low cost. It is suitable for liquid and colloid lithium ion batteries, small and medium-sized polymers, especially for power batteries with high power.
Then, the capacity and cycle performance of the spinel lithium manganate battery were optimized. In the electrolyte of lithium ion battery with spinel lithium manganate as cathode material, nano magnesium oxide is added as deacidifying agent to deacidify the electrolyte, the addition amount is 0.5-20% of the weight of the electrolyte. By deacidifying the electrolyte, the content of free acid HF in the electrolyte was reduced to less than 20ppm, the dissolution of LiMn2O4 by HF was reduced, and the capacity and cycling performance of LiMn2O4 were improved.
Finally, in the first step, nano-sized magnesium oxide was mixed with an ammonia solution as a complexing agent as an alkali solution of pH regulator, and added to the mixed aqueous solution containing cobalt salt and nickel salt to co-precipitate Ni-Co composite hydroxide.
In the second step, lithium hydroxide is added to the Ni-Co composite hydroxide and the mixture is heat treated at 280-420℃.
In the third step, the products generated in the second step are heat treated in the environment of 650-750℃, which is related to the time of co-precipitation. Therefore, the average particle size of lithium composite oxides decreases or the bulk density increases. When lithium composite oxide is used as the anode active material, a high capacity lithium ion secondary battery can be obtained, and the actual addition amount of magnesium oxide depends on the specific formula.