How is lithium hydroxide used in batteries?

Lithium hydroxide is a white monoclinic fine crystal. Lithium hydroxide has a spicy taste and is highly alkaline. Lithium hydroxide in the air, it will absorb carbon dioxide and water. It is a chemical soluble in water, lithium hydroxide is slightly soluble in ethanol, insoluble in ether, is a corrosive substance.

I. The application of lithium hydroxide

Lithium hydroxide can be used as a spreading agent and lubricating oil for spectral analysis. Alkaline battery electrolyte additive, can increase battery capacity by 12% ~ 15%, improve the service life of 2 ~ 3 times.

It can be used as a carbon dioxide absorber to purify the air in the submarine. The chemical equation is as follows:

2LiOH(s)+CO2(g)=Li2CO3(s)+H2O(l).

Used for lithium salt and lithium grease, alkaline battery electrolyte, lithium bromide refrigerator absorption solution, lithium soap (lithium soap), lithium salt, development solution or as analytical reagents; Petroleum, chemical, light industry, nuclear industry, etc. When used for alkaline battery, aluminum content is not more than 0.06%, lead content is not more than 0.01%. Used as analytical reagent, photographic developer, also used in the manufacture of lithium; To be used as a raw material for the preparation of lithium compounds. It can also be used in metallurgy, petroleum, glass, ceramics and other industries.

II. Preparation of lithium hydroxide

1. Complex decomposition method

Lithium hydroxide is usually prepared by mixing lithium carbonate and lime milk into a slurry, heating with 100℃ steam, and filtering out calcium carbonate. This method is commonly used.

Li2CO3 (s) + Ca (OH) 2 = 2 LiOH (s) + CaCO3

2. REDOX method

Lithium metal is prepared by the action of water. The raw material of this method is more expensive and less used.

2Li+2H2O=2LiOH+H2↑

3. Lime sintering method

(1) Spodumene concentrate (generally containing 6% lithium oxide) is mixed with limestone and finely ground, sintered at 1150 ~ 1250℃ to produce lithium aluminate and calcium silicate. After wet grinding and grinding, lithium hydroxide is leachated with lotion. After sedimentation and filtration, the leachate is evaporated and concentrated to crystallize into lithium hydroxide monohydrate products.

Li2O·AI2O3·4SiO2+8CaO→Li2O·Al2O3+4[2CaO·SiO2] Li2O·AI2O3+Ca(OH)2→2LiOH+CaO·AI2O3 (2) under agitation, industrial lithium hydroxide is dissolved in cold water, and the insoluble substance is filtered out. The filtrate is heated and evaporated until crystallization occurs. After cooling, it is dried to prepare a hydrated lithium hydroxide reagent.

(3) Anhydrous lithium hydroxide can be obtained by using lithium hydroxide monohydrate as raw material and drying for several days in a dryer equipped with phosphorus pentoxide. It can also be made by slowly heating lithium hydroxide monohydrate in a hydrogen stream to 140℃ for dehydration.

III. Lithium hydroxide storage precautions

1. Store in a dry and clean warehouse. Keep away from fire and heat. Protect from direct sunlight. The package is sealed. It should be stored separately from oxidants, acids, carbon dioxide and edible chemicals, and should not be mixed. The storage area should be equipped with suitable materials to contain leaks.

2. Transport precautions

The railway transportation shall be carried out in strict accordance with the loading table of dangerous goods in the Transport Rules of Dangerous Goods of the Ministry of Railways. The packing should be complete and the loading should be safe. During transportation, ensure that the container does not leak, collapse, fall, or damage. It is strictly prohibited to mix with oxidants, acids and edible chemicals. During transportation, transport vehicles should be equipped with leakage emergency treatment equipment. During transportation, it should be protected from exposure, rain and high temperature. Road transport should follow the prescribed route, do not stay in residential and densely populated areas.

3. Scrap

Treatment and neutralization in sewage treatment plants. If possible, reuse containers or bury them in designated places. When the amount is small, neutralize the aqueous solution of the product, filter out the solid for burial disposal, and flush the solution into the sewer. The reaction produces heat and smoke, which is controlled by controlling the rate of addition.