Magnesium oxide is a familiar inorganic material, it is a fairly common alkaline oxide, is the main raw material for the production of magnesium hydroxide and magnesium metal. However, with the upgrading of industrialization and the demand and development of high-tech functional materials market, fine magnesium oxide products, especially nano-magnesium oxide began to get the attention of various industries.
As nanoscale magnesium oxide is a new type of nanomaterials, with obvious small size, large surface effect, quantum size effect and macroscopic tunneling effect, the surface has been modified treatment, no agglomeration phenomenon, there is a better dispersion and nano-activity in the system, so it can be very good to play the nano-magnesium oxide particles of the light, electricity, magnetic field, heat, quantum effect, so that the performance of the products with the addition of nano-magnesium oxide has been greatly improved! –So nano-magnesium oxide is often used in battery materials to improve the battery’s cycling and charge/discharge times, to extend the service life of the battery.
1. Application in lithium batteries
①Anode material additives
The high-capacity tin composite negative electrode material of lithium-ion battery is selected to add 10-100g/L of insoluble solid particles such as SiO2, TiO2, ZrO2, Cr2O3, Fe2O3, CeO2, MgO, SiC, and BaSO with a diameter between 0.05 and 10 microns; this method The prepared nickel-solid particle-tin composite negative electrode material has high specific capacity, high first charge and discharge efficiency, and stable cycle performance as a negative electrode for lithium ion batteries.
By adding an appropriate amount of nano-magnesium oxide to the cathode material of a lithium-ion battery, the resulting cathode material has a reversible discharge capacity of greater than 140mAh/g and good cycle performance. Used in cathode materials to improve conductivity, the recommended addition amount is 0.3-0.5%.
②Cathode material dopant
Using nano-magnesium oxide as a conductive dopant, a magnesium-doped lithium iron manganese phosphate is prepared through a solid-state reaction, which further produces a nanostructured cathode material with a conductivity of up to 10-2S/cm and an actual discharge capacity of 240mAh/ g. This new cathode material has the characteristics of low price, high energy and safety. It is not only suitable for small and medium-sized polymer, colloidal and liquid lithium-ion batteries, but is especially suitable for high-power power batteries.
③Electrolyte deacidification agent
Magnesium oxide can also optimize the capacity and cycle performance of spinel lithium manganate batteries. In the lithium-ion battery electrolyte using spinel lithium manganate as the cathode material, nano-magnesium oxide is added as a deacidification agent to remove acid, and the addition amount is 0.5-20% of the weight of the electrolyte. By removing acid from the electrolyte, the content of free acid HF in the electrolyte is reduced to less than 20 ppm, which reduces the dissolving effect of HF on LiMn2O4 and improves the capacity and cycle performance of LiMn2O4.
④Preparation of pH regulator for electrodes
Nano-magnesium oxide can be added to a mixed aqueous solution containing cobalt salt and nickel salt to co-precipitate Ni-Co composite hydroxide. The specific steps are to add lithium hydroxide to the composite hydroxide, heat-treat the mixture at 280~420°C, and then heat-treat the product obtained in the above steps at 650~750°C. When this lithium composite oxide is used as an anode active material, a high-capacity lithium ion secondary battery can be obtained. The addition amount of nano magnesium oxide is about 5%.
2、Application in zinc-nickel battery
Through the physical mixing method in the zinc negative active material doped magnesium oxide, can reduce the charge and discharge polarization, reduce the cycle of the late internal resistance, improve the utilization rate of the negative plate active material, prolong the cycle life of the battery, the appropriate amount of magnesium oxide added 1.0% wt, and should not be added more than 2.0%.
3、Application in high zinc chloride battery
Add a small amount of magnesium oxide in the positive active material can regulate the acidity of the electrolyte, slow down the self-discharge, inhibit the expansion of the battery, improve the storage performance, and to improve the discharge capacity and promote the paste layer paste has a unique effect. It is recommended to add 0.5-1%, and adjust the appropriate PH value.
4、Cadmium nickel battery applications
Add the appropriate amount of magnesium oxide, zinc oxide and iron oxide in cadmium electrode can improve the utilization rate of active substances; add magnesium oxide, indium trioxide and zinc oxide, can improve the charge retention capacity of sealed cadmium-nickel batteries.