Accessories of lithium batteries -- what is the development status of domestic high-end waterborne binders?

The domestic rate of lithium-electric materials is generally high, but the domestic high-end waterborne binders as auxiliary materials are almost blank, which makes people think deeply.

The function of the binder is to adhere to the positive and negative electrode material and the conductive agent firmly to the metal-collecting fluid to form a positive and negative polar plate of the battery. The amount of binder used in positive and negative electrode tablets is very small, accounting for no more than 3 % of the cost of lithium batteries. However, as a connecting medium of electrode active materials, it has an impact on the performance of battery resistance, first effect, multiplier, and high temperature. It is an accessory that can not be underestimated.

At present, the binder used for positive mixing is mainly an oily binder PVDF. This kind of binder needs to be added to the NMP solvent for use. The NMP solvent contains some harmful substances that are harmful to human health and needs to be recovered at input cost. Initially, the binder used for negative pole mixing was also an oil-based binder such as PVDF. However, because of the serious polarization in the battery and the Environmental Protection of the water system and the ability to replace its bonding effect, the development of the negative pole has now used water system binders. Become in the mainstream direction.

Water binders mainly include SBR(butadiene emulsion), CMC (hydroxymethylcellulose), PTFE (polytetrafluoroethylene emulsion), PAA(polyacrylate) and the like. It can be used in conjunction with lithium iron phosphate in a positive material, and it can also be used in part of lithium manganate(different lithium manganate), but it is incompatible with ternary materials and there are technical difficulties that are difficult to overcome. And ternary materials, especially high nickel ternary, is the general trend of the industry so that the expansion of waterborne binders in the positive field has become more difficult.

However, there are also senior people who believe that with the tightening of national environmental protection policies(the European Union has introduced a policy to ban the sale of oily system binders, China or the wind), As well as internationally renowned waterborne binders manufacturers such as Japan's Rion and JSR are increasing research and development to try to overcome the technical difficulties of positive waterborne binders. In the future, waterborne binders are expected to gradually replace PVDF. Of course, replacing PVDF will win some market space, but the key to future sales growth is still the expansion of the downstream power battery market.

According to the survey data, the overall demand for waterborne binders in 2017 is about 2,000 tons, and it is expected to reach a scale of 4,000 to 5,000 tons by 2020. The increase in demand will mainly come from the power cell field. At present, power batteries have formed a highly concentrated situation, and the top 10 companies have a market share of more than 70 %. This also means that high-end power battery companies can fully enjoy the dividends of the development of power batteries in the customer structure of waterborne binders manufacturers.

A cruel reality in front of us is that the current high-end water-borne binder market is almost the world of Japanese companies such as Ruiweng, JSR, and Shuangri, while the more well-known water-borne binder brand in China is Chengdu Yin Dole(now a wholly-owned subsidiary of China Branch). Other domestic brands can be described as "barely heard".

The high-end price of waterborne binders is 300-400 yuan/kg, and the low end is only 20-30 yuan/kg. The price difference is more than ten times, and the profit space cannot be compared at all.

The page contains the contents of the machine translation.