Because of its high hardness level, tungsten carbide is widely used as super hard cutting tool and wear resistant material. The application of tungsten carbide coating has become more and more popular at home and abroad since battery manufacturers raised their requirements on magnetic foreign bodies of cathode materials in 2014. In the lithium battery material manufacturers we visited and communicated with, their feedback in the application is that the coating thickness, process, surface smoothness, compactness and bonding strength of tungsten carbide coating imported from foreign countries, especially Germany, Japan and South Korea, is one grade higher than that of domestic manufacturers. And small to think not abroad equipment, how advanced the technology, spraying domestic manufacturers more is limited by price, technical workers craft two factors lead to relatively less abroad, domestic sprayed tungsten carbide coating price 7000 yuan has been spraying within a square, even spraying area is large, the tungsten carbide coating cost stood there. The manufacturer gives 7000 yuan to make one square meter, then the spraying manufacturer will save the material cost in the following aspects: Sandblasting material cost control, coating tungsten carbide material cost control, coating thickness control, compactness, smoothness control operation, each part of the cost control these ultimately affect the quality of the final spraying out of tungsten carbide coating and of course the price is really low to 7000 yuan, but production enterprises should be able to find, spraying of the tungsten carbide coating can be used for half a year abroad, and domestic low sprayed tungsten carbide coating can only use two or three months, or even a week wear bigger place is glittering, will remove the secondary spraying returned to the factory.

Today we talk about the three SINS, not to say that tungsten carbide coating is not good, but the application of lithium anode materials are inappropriate in three aspects:

The first crime: wear cycle is short, many times a year spray coating, increase the cost of coating. Tungsten carbide mohs hardness hardness level is very high 70 degrees, but sprayed tungsten carbide coating thickness is 0.1 mm to 0.3 mm, wear and tear strength small cone mix can make do with one or two years time, but the function of high speed mixing of wear and tear strength enough about three months, some of the enterprise production process of ternary material, wear in the process of cobalt acid lithium production badly, can only use half a month or even a week. According to the calculation of 3 months on average, spraying is done 4 times a year. If a production line is calculated by 30 horizontal volume, four times a year is 120 square meters. According to the average price of 120 square meters, 8,000 yuan, that is the cost of 960,000 yuan of spraying coating, which has not added the logistics cost of equipment transportation back and forth.

The second crime: disassembling and returning to the factory, the cycle is long. With the national policy orientation, now lithium battery anode material enterprises are springing up like bamboo shoots after a spring wind, many powerful enterprises hope to take a place in this energy reform, some enterprises are so true, one more concept, let the enterprise stock can rise in response to the situation. Some companies are so busy with orders that the value of a day's shutdown can run into millions of yuan. Remove back to factory spray coating, transport cycle, back to factory installation. The process can take anywhere from three days to half a month, and if there's no replacement line, the damage can run into the millions and tens of millions.

The third crime: tungsten carbide coating high temperature easy "loss of carbon" oxidation into metal foreign body, another in 500 degrees Celsius ~800 degrees Celsius air suffered serious oxidation. Tungsten carbide is insoluble in water, hydrochloric acid and sulfuric acid, and is easily soluble in mixed nitric acid-hydrofluoric acid. For the production process of lithium anode material, precursor and lithium extraction stage, no matter the oxidation reaction of tungsten carbide coating adds metal foreign matter, or the coating is corroded away, it will have an adverse impact on the finished battery material.

Wear short cycle, remove the returned to the factory repair coating cycle long, the tungsten carbide coating on high temperature oxidation reaction such as "three SINS" described above, unless it is wear and tear is small, or continuous wear corrosion of the surface of the equipment can use the tungsten carbide coating, suggest li-ion battery cathode material production enterprise in wear and corrosion on the above choice carefully consider using tungsten carbide coating. You can use other metal layers to avoid the above problems.