button battery cr2032

What kind of diaphragm does LG Chem use for its power button battery cr2032?

The answer is: both dry and wet diaphragms are used, but dry diaphragms account for a larger proportion.

Not only LG Chem, but also Samsung SDI and AESC (for Nissan) mainly use dry-process power batteries (supplier Celgard).

Since 2013, LG Chem's main supplier of dry-process diaphragms has been replaced by Celgard.

As for wet-process diaphragms, there are currently many partners, at least Toray, W-scope and Star Source Materials. The coating plants and base film production lines of the first two are still purchased from LG Chem, and Star Source Materials has obtained the patent license for LG Chem's SRS coating. Therefore, LG Chem's power batteries use wet-process diaphragms, and Star Source Materials is likely to be its main supplier.

Special note: Ube Industries of Japan, which does dry-process, has also obtained the patent license for SRS, but has not yet become its supplier.

There have been many rumors about the diaphragm supplier of LG Chemical's power batteries in the market recently. We can summarize them into the following two types:

LG Chemical's power batteries all use wet-process diaphragms from Japan's Toray, and the dry-process diaphragms supplied by Xingyuan Materials are used in low-end fields such as power tools and energy storage.

In addition to using Toray's wet-process diaphragms, LG Chemical uses Celgard's dry-process diaphragms, which have nothing to do with Xingyuan Materials.

If the above rumors are true, then the logic mentioned at the beginning that "Xingyuan will most likely become LG's main supplier" is obviously wrong, so it is necessary to explain here which diaphragm LG Chemical's power batteries use.

In order to ensure credibility during the analysis, the data sources only select prospectuses, announcements, and authoritative third-party reports, and do not use research minutes with lower credibility.

Let's talk about the second rumor first. We think it is not worth refuting. It can be seen in Xingyuan Materials' prospectus that since 2013, the company has formed a batch supply to LG, and the sales revenue that year reached more than 30 million yuan.

The top few customers shown in the prospectus of Xingyuan Materials:

After that, Xingyuan Materials' sales volume increased year by year. By 2017, its export revenue had grown to 194 million yuan (most of its overseas revenue came from LG Chem), and its sales volume was nearly 60 million square meters. It is undoubtedly one of LG Chem's core suppliers.

In fact, LG Chem's dry-process diaphragm supplier has been replaced by Xingyuan since 2013.

There are two reasons:

LG Chem and Celgard's parent company Polypore had already gone to court over patent issues as early as January 2014. Celgard sued LG Chem on the grounds of LG Chem's diaphragm patents, demanding that LG be prohibited from selling related batteries in the United States. For a supplier that sued itself, I think no battery factory would consider purchasing it again.

Since July 2013 (the same time as Xingyuan's large-scale entry into LG Chem), the supply between Celgard and LG Chem has basically stagnated. After losing this important customer, its revenue has also declined year by year, and it was finally acquired by Asahi Kasei in 2015.

As for the first rumor, that is, what are the downstream application fields of the dry-process diaphragm that Xingyuan provides to LG, it is more difficult to analyze. Let's try to analyze it.

LG Chem's power battery must be using Xingyuan's dry-process diaphragm

From the analysis of the material system of Chevrolet Volt (LG Chem's power battery flagship model) by the authoritative organization Avicenne, there are both PP (dry process) and PE (wet process), and the common point is that they are all coated.

Another authoritative report shows that LG Chem's PHEV and HEV batteries both use dry-process diaphragms + SRS material coating. (The figure below also shows that Nissan's electric car AESC battery also uses dry-process diaphragms)

From Xingyuan's prospectus, since 2015, more than 90% of its products have been used in the power field. And LG Chem accounts for more than 30% of its shipments, so most of them must be used in the power field, replacing the original Celgard dry-process diaphragm.

There has always been a misconception in the market that dry-process diaphragms can only be used in low-end fields, such as power banks, energy storage batteries, lithium iron phosphate power batteries, etc., and higher-end ternary power batteries must use wet-process diaphragms.

The actual situation is completely the opposite. Not only LG Chem, but also Samsung SDI and AESC (for Nissan Leaf) use dry-process diaphragms as the main power batteries. The following two pictures are the battery material systems of Samsung SDI and AESC given by the authoritative organization Japan B3.

AESC supplies 32.5Ah power batteries for Nissan Leaf, which still uses Celgard's PP (dry-process) diaphragm. (PP is polypropylene, used for dry-process diaphragms; PE is polyethylene, used for wet-process diaphragms; separator is a diaphragm)

Samsung SDI supplies BMW with 60Ah and next-generation 94Ah power batteries for i3, and still uses Celgard's three-layer PP/PE/PP (dry-process) diaphragms.

SRS is LG Chem's unique skill, and Xingyuan has obtained authorization

According to a report from the authoritative Japanese B3, the diaphragm industry has been divided into two camps, the LG camp (including Toray, W-scope, Xingyuan, etc.) and the Asahi Kasei camp (including the acquired Celgard).

LG Chem has a unique technology for SRS coating of diaphragms, and the companies in its camp have partially or completely obtained the technology of this coating. Xingyuan and Ube Industries have obtained SRS patent authorization (in the future, they will need to pay part of the patent royalties to LG Chem for the sale of such diaphragms). Although Ube Industries has also obtained authorization and is also engaged in dry-process diaphragms, LG has not purchased from it yet, but is only an alternative supplier. The original words of B3 are "The Ube Maxell product is also acandidate for use in LG CxEV cells 4".

Toray directly acquired LG Chem's coating plant at a price of 3 billion yen (equivalent to about 184 million yuan), and W-scope purchased LG Chem's wet-process diaphragm production line. Therefore, LG Chem no longer produces coated diaphragms by itself, but has turned to purchasing them from external suppliers. (The picture below is the original picture of B3, and Senior is Xingyuan Material)

LG Chemical batteries have been selected as designated battery suppliers by international automobile companies such as General Motors, Renault, and Nissan. SRS diaphragm coating technology has played a decisive role. Therefore, Xingyuan has obtained patent authorization and will undoubtedly occupy an important position in the future LG Chemical power battery map.

The proportion of wet-process diaphragms will increase, and Xingyuan needs to compete with Toray and W-scope

As mentioned earlier, LG Chemical's power batteries use both dry-process and wet-process diaphragms. In terms of dry-process diaphragms, Xingyuan Materials has replaced Celgard and become the core supplier of LG Chem, and there are no strong competitors, and its position is stable.

However, from the perspective of the development trend of lightweight and thinning, wet-process diaphragms will still be the direction in the future. A research report from B3 shows that Renault's second-generation ZOE in 2020 will use SRS-coated wet-process diaphragms.

LG Chem has many suppliers of wet-process diaphragms, and the equipment of the two membrane companies, Toray and W-scope, all come from LG Chem itself. They have close ties with LG Chem, so Xingyuan faces more competition.

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