On July 14th, SES solid-liquid hybrid battery company located near Boston, USA announced a backdoor listing, with IvanhoeCapital as the backdoor target and trading code IVAN on the US stock market. After going public, the valuation of SES company will reach 3.6 billion US dollars, far exceeding its competitor Solid Power's 1.2 billion US dollars just went public last month, and also surpassing Quantum Scape's 3.3 billion US dollars, making it the most valued solid-state battery startup among all listed companies.

SES Company was founded in 2012 by Dr. Hu Qichao, who had just graduated from MIT. Initially located near Boston, it later opened branches around the world with the concept of following market layout. Now its nominal headquarters is located in Singapore, production and research and development are located in Boston and Shanghai, and sales and research and development departments are also established in South Korea. In April of this year, SES just received a Series D financing of $139 million led by General Motors, announcing the successful deployment of solid-state battery technology by the largest car manufacturers in Europe and America. Click on the link to read about Quantum Scape, a company invested by Volkswagen, and Solid Power, a company invested by Ford and BMW, which we have previously introduced.

With the announcement by the US Securities and Exchange Commission two months ago that it would strengthen regulations on shell companies, which would increase the difficulty of backdoor listings in the future, many startups are seizing the last opportunity to go public through backdoor listings. Solid Power, which went public last month, just received Series B financing and announced its listing a month later; Now, SES is also rushing to go public after just obtaining a financing of over 100 million US dollars, giving investors in the secondary market several more options to invest in future solid-state battery technology. However, since QuantumScape's stock price fell back to its prototype from last year's strong winds, investors are now more cautious about the stock price of solid-state battery companies. As of today, the stock prices of Solid Power and SES have both fluctuated around $10, which is the issue price of their stocks. However, we can see from SES's investment promotion document (see reference at the end of the article) that there is an incentive measure for existing stock and option holders: if the company's stock price exceeds $18 per share one year after successful listing, existing shareholders and holders will receive an additional 30 million shares. If I were an employee or investor of SES company, in order to obtain this additional 30 million shares, I would also work hard to improve the products and push up the company's stock price. If you think about it this way, if you buy some circulating stocks for $10 per share now, you may achieve a minimum return of 80% in one year (risk warning, this article does not constitute investment advice).

The reason why SES can obtain valuations higher than Quantum Scape and Solid Power is because its technological maturity surpasses those two companies. From the technology comparison disclosed in the investment promotion document, SES has successfully achieved 70% energy storage after 779 cycles of charging and discharging 3-4 layer Pouch Cells, while 25 layer Pouch Cells can maintain 90% energy storage after 550 cycles of charging and discharging. The cycling performance of its 3-4 layer soft pack battery is different from QuantumScape, while the 25 layer soft pack battery is a technological height that the other two companies have not yet publicly achieved. On the other hand, as SES still uses liquid electrolyte, it is easier to utilize existing lithium battery production lines for large-scale production, and the use of liquid electrolyte also avoids some of the challenges of solid-state batteries.

Through the analysis of several all solid state battery technologies, we have learned that due to the use of solid electrolytes, the negative electrode material of all solid state batteries will inevitably expand and contract during charging and discharging. Therefore, it will inevitably create gaps between the solid electrolyte that surrounds it, or seriously reduce the contact between the two, resulting in partial failure of the negative electrode material or high internal resistance, greatly reducing battery efficiency. Therefore, all solid state batteries usually require a large external pressure, such as dozens of atmospheres, to ensure that there is no gap between the internal negative electrode material and the solid electrolyte. While using metallic lithium as the negative electrode material, SES still manages to use liquid electrolytes, relying on their fluidity advantage to solve the above problems. However, liquid electrolytes also have some problems, such as reacting with lithium metal, unable to block the formation of lithium metal dendrites, and being prone to heat volatilization, which can cause flammability and explosion. How does SES solve these problems?

SES listed several key technical features in its investment presentation document, including:

1. Use ultra-thin lithium metal negative electrode coatings to minimize their volume expansion amplitude as much as possible;

2. Apply a special protective coating on the negative lithium metal;

3. Use polymer membranes with self power-off function;

4. Use liquid electrolytes containing high concentrations of inorganic salts.

Through research on the patents applied by SES, we have made some deeper detailed speculations on the above-mentioned characteristic technologies. The solution of liquid electrolytes containing high concentrations of inorganic salts has been studied by the academic community for several years, so it is not considered a unique technology of SES. However, SES has its unique electrolyte formula. Its application feature is that when liquid electrolytes contain high concentrations of inorganic salts, almost all electrolyte molecules will form weak binding with the inorganic salts through hydration, and can no longer freely move or evaporate, thus solving the problem of easy volatilization and explosion of liquid electrolytes.

SES has innovatively applied for two different negative electrode material protective coatings patents. The first patent designed two layers of polymer protective coatings. The layer adjacent to the lithium metal is composed of a relatively dense polymer material with ionic groups, which can prevent the liquid electrolyte from coming into contact with the lithium metal through the protective layer and prevent the penetration of lithium metal crystal branches. At the same time, the ionic groups provide a channel for lithium ions to enter and exit. The protective layer next to the diaphragm is composed of flexible polymers with a porous structure, and electrolytes or ionic liquids can be placed in the gaps to form ion conduction channels. This flexible polymer layer can shrink and expand with the expansion and contraction of the lithium metal negative electrode, to compensate for the spatial deformation caused by the lithium metal layer and solve the problem of excessive deformation of the negative electrode material. The second patent only designed a protective layer, which is made of cross-linked polymer and reinforced fibers. Its function is similar to the dense protective layer in the first patent, and it does not look as complex and advanced as the first patent.

Another innovative patent of SES is about polymer membranes with self power-off function. The polymer membrane they designed has a porous structure, with another type of copolymer polymer microspheres attached to both sides or gaps. The microspheres also have a porous structure that allows lithium ions to pass through. The melting temperature of the microspheres is much lower than that of lithium metal (179 degrees). When thermal runaway occurs inside the battery and the temperature rises to the melting temperature of the microspheres, the microspheres will melt and form a dense film, blocking the passage of lithium ions, thereby cutting off the current from inside and preventing the temperature from further rising to the melting point of lithium metal.

In summary, SES attempts to use innovative technologies to solve the problem of liquid electrolytes and lithium metals, which is thought-provoking and very inspiring. Both SES's solid-liquid hybrid battery and Solid Power's silicon negative electrode solid-state battery are intermediate fusion technologies between traditional lithium-ion batteries and lithium-metal all solid-state batteries. In terms of technical development difficulty, they should be lower than lithium-metal all solid-state batteries, so they may achieve success earlier. So let's wait and see the rapid development of SES, and look forward to seeing more battery pack test data soon to prove the merits of this solid-liquid hybrid battery technology!

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Reference:

one https://ses.ai/downloads/ses_investor_presentation.pdf

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Author Introduction:

Dr. Xie Wei, Bachelor and Master of Materials Science from Tsinghua University, and Ph.D. in Chemical Engineering from the University of Texas (Austin) in the United States. Mainly engaged in the development of energy storage batteries, has held important positions in multinational corporations and startups, led multiple research and development projects funded by the US Department of Energy, and won the 2013 US Annual 100 Best Research and Development Technology Award. Published 17 papers in top journals in materials science and energy storage, served as a reviewer for 5 international journals, and has applied for 17 international invention patents.

Introduction to ZH Energy Storage Company:

Shenzhen ZH Energy Storage Technology Co., Ltd. is committed to the research and development, promotion, and application of energy storage technology, aiming to help achieve China's goal of "carbon neutrality" through the application of electrochemical energy storage technology. In the early stages of development, the company focused on providing technical support and consulting services to the Chinese energy storage market by leveraging its accumulated industry experience and outstanding research and development capabilities in the field of energy storage. At the same time, the company focuses on conducting research and analysis on the Chinese energy storage market, and developing or introducing the most advanced and effective energy storage technologies for the Chinese market.

Company's technical research and development direction: water-based energy storage batteries, lithium-ion battery materials, fuel cells, ion exchange membranes, coatings and adhesives, membrane separation technology.

Domestic business: Technical cooperation and academic exchange between liquid flow batteries and high-energy density lithium-ion batteries, technical lectures on the company's technology research and development direction, research and development consulting, and guidance on paper writing.