Editorial: Recently, the 2022 Lithium Battery Materials Convention, hosted by Gaogong Lithium Battery of GGII, kicked off in Chengdu. In the opening ceremony, Dr.Wu Huikang, premier scientist of SEMCORP and senior vice principal, did a keynote speech themed “Lithium-ion Battery Separator Technologies Road Map and Development Trends”. This article has excerpted essential portions for the readers.

Benefiting from the globalization of carbon neutrality, the new energy industry is entering an acceleration phase, which means every country will gradually shift to generating power with clean energies. The boom in the EV industry paves the way towards carbon neutrality.

As one of the four main materials, separator plays a critical role in the integrity of power batteries and expense control through its own technological innovations and functionality improvement. There are 6 main trends in the road map and market development of separator: 

I. Power Density is Improving Further and Separator Base Diaphragm is Sustaining the Trend Towards Thinning.

At present, the mainstream lithium-ion battery application is markedly dichotomized into two main fields—dry and wet technologies. Separator with dry technology is mainly used for buses, electric tools and power storage while separator with wet technology is mainly used for passenger vehicles and consumer electronics. Compared to common base diaphragm with nano-puncture structure, the low blind foramen temperature base diaphragm developed by SEMCORP can close up the nano-puncture in low temperatures when thermal runaway happens, so as to effectively stop chemical reactions inside the battery.

Ⅱ. Battery Enterprises Have been Increasing Demands for Safety and Processability, Which Further Increases the Share of Coating Diaphragm

Battery enterprises puts increasingly more stress on battery safety. Functional coating diaphragm has an advantage in improving separator’s heat resistance, preventing separator oxidization on the anode and preventing piercing of separator by lithium plating on the cathode. Furthermore, separator’s adhesion can also be increased, which can facilitate casing of battery cell and improve manufacturing productivity of battery cells; increase the strength of battery soft packages to prevent deformity and increase recyclable life span. At present, SEMCORP has the most complete separator product layout which includes PE base diaphragm, CCS coating products, PCS coating products, MFS coating products, etc.

Ⅲ. Export Is Growing Rapidly and Obvious Problems Are Emerging on IP Rights

At present, the industry of power batteries is developing rapidly towards globalization, during which IP rights are given increasing weight amid the competition. SEMCORP highly values its IP right structure. As of Jun. 30, 2022, SEMCORP has 502 effective patents and has achieved mutual sharing and authorization of technologies and IP rights with industry giants that possess core patents in base diaphragm and coating such as Korea, Japan and the US. Meanwhile, the company has also signed long-term service agreements with well-known American IP right law firms Finnegan and Jones Day.

Ⅳ. Constantly Reducing Cost; Integration of Base Diaphragm Equipment Has Become a Trend.

The technologically integrated “base diaphragm-coating” assembly line developed by SEMCORP can improve quality and productivity and reduce loss, making it an effective tool to reduce cost, improve productivity and to improve core competitiveness.

Ⅴ. The New Energy Market Is Growing Fast; Active Expansion for Guaranteeing Delivery

SEMCORP is an industry leader in wet lithium-ion battery separator and has entered supply chains for most of the global mainstream lithium-ion battery manufacturers. Main clients include Panasonic, SAMSUNG, LGES, CATL, CALB, BYD, GOTION HI-TECHNOLOGIES, Farasis Energy, Tianjin LISHEN, etc. In order to meet the vigorous demand of the global market, the company is proactively working on its global presence and has established production bases in Shanghai, Zhuhai, Wuxi, Jiangxi, Suzhou, Chongqing (Chongqing Niumi Technology), etc.. Planned new bases include locations in Hungary, the US, and Chinese cities such as Jiangsu, Hubei, Yuxi, Xiamen, etc.

Ⅵ. Next Generation of Separator Will Develop Towards Half-Solid Composite Diaphragm

Quasi-solid battery is a rising star which boasts advantages such as high safety, high power density, technological compatibility, modest cost, etc.. Solid electrolyte coating diaphragm features high ionic conductivity, high strength, fine processability, low cost, etc., and will become a core part of quasi-solid battery. In April of this year, SEMCORP established a joint venture with IOPSILION and Beijing Welion in solid electrolyte coating diaphragm for semi-solid battery. The three companies will together research and develop separator products for semi-solid and solid lithium-ion batteries.