A "business war" between a global battery giant and a rapidly rising energy storage newcomer has been thrust back into the spotlight due to a letter of appeal from an executive's wife.

On the evening of September 15, a user claiming to be "Feng Dengke's wife" published through a WeChat public account "Feng Dengke's Wife's Letter of Appeal: Please Don't Let My Husband Become a Victim of Malicious Business Competition" (hereinafter referred to as the "Letter of Appeal"). The letter states that her husband, Feng Dengke, former director of the president's office and head of the engineering department at Haichen Energy Storage, was arrested by CATL on charges of infringing commercial secrets.

The letter mentions that when Feng Dengke left CATL in 2017, he was only a low-level P8 equipment engineer. He joined Haichen Energy Storage in the second half of 2020 - he doesn't understand complex business competition, let alone so-called "commercial secret" disputes... But on July 13, 2025, everything was shattered when Feng Dengke was taken away by Fujian Ningde police at Xiamen Gaoqi Airport on his way home from a business trip, and has not returned since.

Feng Dengke joined Haichen Energy Storage in the second half of 2020 as director of the president's office and head of the engineering department. However, sources close to Haichen Energy Storage previously revealed that starting from 2024, Feng Dengke was no longer employed by Haichen Energy Storage and was not a company executive. His current position is President of Haichen Green Energy (Shanghai) Energy Development Co., Ltd., responsible for business development in the commercial field, unrelated to technology, and his previous president's office position was also unrelated to technology.

Feng Dengke's wife questions this as "malicious business competition" in the letter and states that her husband may become a victim.

Currently, neither CATL nor Haichen Energy Storage have responded to this matter.

**Long-standing Intellectual Property Disputes**

In fact, the intellectual property disputes between CATL and Haichen Energy Storage have a long history. Before the criminal report, CATL's civil rights protection had already begun. In June this year, CATL sued Haichen Energy Storage and its actual controller Wu Zuyu and 7 other defendants for "unfair competition," alleging that they poached technical teams and copied patented technologies, resulting in highly overlapping cell product parameters between both parties, and seeking 150 million yuan in damages.

In September 2023, CATL had sued Wu Zuyu for violating non-compete agreements, ultimately resulting in Wu Zuyu's wife Lin Xiuhua paying 1 million yuan in breach of contract penalties on his behalf.

In November 2023, CATL sued another employee, Zhang Min, for violating non-compete agreements, again involving Haichen Energy Storage. Zhang Min left CATL at the end of 2021 and joined Xiamen Rare Earth Materials Research Institute. However, CATL photographed Zhang Min multiple times wearing Haichen Energy Storage badges entering and leaving Haichen Energy Storage facilities in 2023, believing that while at Xiamen Rare Earth Materials Research Institute, Zhang Min was actually serving Haichen Energy Storage, violating non-compete restrictions, and demanded 1 million yuan in breach penalties.

From frequent movement of core talent to fierce competition over commercial secrets, and then to courtroom confrontations over unfair competition disputes, the conflicts between the two companies continue to escalate. For Haichen Energy Storage, which is at a crucial IPO stage, this series of incidents undoubtedly adds obstacles to its listing path.

However, regarding Feng Dengke's arrest, sources close to Haichen Energy Storage previously stated in interviews that "the case is still under investigation, and public security has investigation and verification procedures. Whether there are problems, whether there will be sentencing, etc., remain undetermined. What specific commercial secrets refer to is also unclear and remains confidential." The source believes that the aforementioned events have no impact on Haichen Energy Storage's business operations.

As of September 17, CATL A-shares closed at 377.1 yuan per share with a total market value of 1.7 trillion yuan, and Hong Kong stocks closed at HK$502.5 per share with a total market value of HK$2.29 trillion.

**Patent War Affects Employees?**

Feng Dengke's case is related to a patent concerning composite current collectors.

According to CATL's investigation, Shenzhen Haihong New Energy Technology Co., Ltd. (hereinafter "Shenzhen Haihong"), established in the same year as Haichen Energy Storage, applied for 21 patents from 2019-2020, most of which were transferred to Haichen Energy Storage in 2022, including composite current collector patents.

According to Tianyancha, Shenzhen Haihong's supervisor is Lin Lijun, who is also supervisor of Shishi Aijiabei Education Consulting Service Co., Ltd. The largest shareholder of this company is Wang Pengcheng, holding 54%. Wang Pengcheng is the brother-in-law of Haichen Energy Storage's actual controller Wu Zuyu.

CATL suspects this technology involves its commercial secrets and traced back to find that former employee Feng Dengke, after leaving in 2017, went undercover at supplier Jinmei New Materials under the alias "Engineer Ma," participating in CATL's composite current collector outsourcing project.

According to a tripartite agreement obtained by "LatePost," CATL's composite current collector outsourcing project with Jinmei New Materials was actually executed jointly by a project team comprising Jinmei New Materials, Fujian Xinyu, and Xu Caixia, with the three parties signing a cooperation agreement in March 2018.

This "Xu Caixia" was later confirmed to also be a relative of Wu Zuyu. Feng Dengke joined Haichen as director of the president's office and head of the engineering department after the project ended.

It's worth noting that during Wu Zuyu's tenure at CATL, he led the development of key battery technology composite current collectors. From July 2012 to November 2018, Wu Zuyu applied for a total of 67 patents at CATL, involving current collectors, electrode sheets, and batteries in the energy storage field.

Feng Dengke joined CATL in 2016 as an ordinary equipment engineer and was Wu Zuyu's subordinate.

According to Tianyancha, Feng Dengke currently holds shares in Haichen Energy Storage through two shareholding platforms: Xiamen Haichen Chuangxiang and Xiamen Haichen Zhicheng No.1.

However, Feng Dengke's wife states in the "Letter of Appeal" that the so-called "commercial secrets" have already been made public. She points out that the "commercial secrets" CATL accuses Dengke of leaking are technical information from patent No. 202020013754.1 published on July 24, 2020. However, after commissioning 4 professional institutions for search and identification, she found that as early as May 14, 2020, international patent WO2020093375A1 had already disclosed all contents of the said technology. This means that the "commercial secrets" claimed by CATL were already industry-known information before their alleged "leakage time." Feng Dengke's wife further questions how technology without "secrecy" can be considered "commercial secrets."

Shanghai Shenlun Law Firm lawyer Xia Hailong points out that patents and trade secrets are mutually exclusive. Patents exchange disclosure for protection, while trade secrets are protected by rights holders themselves. That is, if there really exists a public patent, it cannot be considered a trade secret. But the question is whether the trade secret and patent in their dispute are the same thing. If they are different, that would be another matter.

Feng Dengke's wife also questions the necessity of forced detention in the "Letter of Appeal," stating that her husband Feng Dengke has Grade 3 hypertension, with blood pressure reaching 165mmHg at the time of detention, and doctors clearly stated "detention risk is extremely high."

"It has been more than 2 months since my husband Feng Dengke was suddenly taken away. During these 2 months, I have to hide this from my over-60-year-old in-laws who suffer from hypertension and heart disease every day... I also have to put on a brave face for my child, answering him 'Dad is working hard to earn money and will come home to accompany you soon'... I never thought that an honest and simple person would suddenly be involved in such a storm, plunging our ordinary family into disaster," Feng Dengke's wife wrote in the "Letter of Appeal."

**150 Million Yuan Claim: Technical Dispute or Rights Protection?**

In addition to this criminal case, there is also an unfair competition dispute case. In June 2025, CATL sued Xiamen Haichen Energy Storage Technology Co., Ltd. and 6 related parties to Ningde Intermediate People's Court.

CATL's allegations focus on two core points: First, Haichen Energy Storage founder Wu Zuyu and his team systematically poached CATL's core technical talent in violation of non-compete agreements; Second, Haichen Energy Storage's 587Ah large-capacity energy storage cells are highly similar to CATL's products from the same period, with energy density deviation of only 4.4%, far below the industry's 10% technical generation gap standard, suspected of technology infringement. CATL seeks 150 million yuan in damages.

It's worth noting that since this year, both Haichen Energy Storage and CATL have coincidentally made large-scale promotions of "587Ah cells" to drive sales.

A 587Ah lithium battery refers to a lithium-ion or lithium polymer battery with 587 ampere-hour capacity. Ampere-hour (Ah) is a unit of battery capacity measurement, used to express the current magnitude multiplied by time that a battery can continuously discharge at a certain discharge rate. Specifically, 587Ah means this battery can continuously discharge for 587 hours at 1 ampere current, or discharge for 1 hour at 587 amperes current.

In March 2025, Haichen Energy Storage participated in the 15th China International Clean Energy Expo with 587Ah cells.

In April 2025, at the 13th International Energy Storage Summit and Exhibition, Haichen Energy Storage stated in a public account article that "at the exhibition, Haichen Energy Storage's ∞Cell 587Ah energy storage battery with dimensions of 73.5*286*216mm (W*L*H) became the focus, with 5 industry-leading companies simultaneously displaying this battery."

Haichen Energy Storage also stated that this industry-level collaboration means that Haichen Energy Storage's 587Ah energy storage battery dimensions have been jointly defined by multiple industry-leading companies for the first time, which may promote the upgrade of "Haichen standards" to "industry standards."

After being sued, Haichen Energy Storage has not reduced its promotional efforts. On July 25, Haichen Energy Storage officially announced the release of the world's first third-generation cascaded high-voltage large-capacity energy storage system based on ∞Cell 587Ah large-capacity batteries on its public account.

On the other hand, CATL has already begun mass production of 587Ah cells.

On June 10, CATL held the "Real Energy" 2025 Energy Storage 587 Technology Day, officially announcing mass production and delivery of the next-generation large-capacity energy storage dedicated cells - 587Ah cells, which will be produced at the Shandong Jining base in the future.

At the event, CATL officials also stated that in response to industry chaos, the company will take creating real value as its philosophy, explore optimal solutions for next-generation energy storage large cells with the industry, and discuss orderly and healthy development.

Zhang Jian, Deputy Secretary-General of the Energy Storage Branch of China Battery Industry Association, said that from the perspective of enterprise competition, companies hope their technical specifications become industry standards because this gives enterprises first-mover advantages within industry standards. However, from the perspective of industry resource allocation, different specifications of cells will spawn numerous different specifications of system integration technologies and products, especially PCS products, which may lead to resource waste.

In fact, over the past few years, whenever CATL launches a new cell, Haichen quickly follows. The competition between the two companies is gradually intensifying.

In 2020, CATL launched 280Ah cells, and Haichen Energy Storage followed with mass production in 2021; in August 2023, CATL mass-produced 314Ah cells, and Haichen mass-produced systems equipped with these cells in November of the same year.

Moreover, Haichen Energy Storage just turned profitable in 2024 with net profit of 288 million yuan, after losses of 1.777 billion yuan and 1.975 billion yuan in 2022 and 2023 respectively.

**Four Lawsuits: The "Grace" and "Grievances" Behind**

Behind CATL's frequent challenges to Haichen Energy Storage is actually a story of "a horse meeting its master."

Haichen Energy Storage's founder is Wu Zuyu, born in 1986, with a bachelor's degree in applied chemistry from Shandong Normal University and a master's degree in chemical engineering from Fuzhou University. He served as an engineer at CATL from 2011-2019.

According to the "List of Incentive Recipients for the First Grant of CATL's 2018 Restricted Stock Incentive Plan," the company provided equity incentives to 1,670 people. Wu Zuyu was one of the middle management personnel granted options.

However, after receiving equity incentives, Wu Zuyu left in 2019.

According to Haichen Energy Storage's prospectus, in December 2019, Zhuhai Haiheng New Energy Technology Partnership (hereinafter "Zhuhai Haiheng"), Zhuhai Huiwei New Energy Technology Partnership, and Wang Pengcheng jointly established Haichen New Energy, the predecessor of Haichen Energy Storage, holding 73.31%, 21.98%, and 4.71% respectively.

In the prospectus, Haichen Energy Storage specifically emphasized that when Zhuhai Haiheng was established, it was ultimately controlled by Wu Zuyu's spouse Lin Xiuhua.

In May 2021, Wu Zuyu officially became legal representative of Haichen Energy Storage. The outside world speculates this was when the non-compete period ended.

Since its establishment, Haichen Energy Storage has been like riding a "rocket," growing rapidly all the way.

According to WeChat public account "Haichen People," Haichen Energy Storage completed everything from land listing transaction to construction permit approval in just 42 days; completed the topping out of the headquarters R&D building in just 80 days; the second phase project took only 3 months from groundbreaking to topping out, creating multiple industry project landing records.

In August 2021, Haichen Energy Storage's first 280Ah energy storage dedicated battery was rolled off the production line in China, with mass production two months later; in 2023, it launched the world's first kiloampere-hour level long-duration energy storage battery (1175Ah), overcoming thermal control and lifespan challenges for large-capacity batteries, securing GWh-level orders; in 2024, the company's overseas revenue ratio rose to 28.6%, with customers covering international giants like Jupiter Power and Samsung C&T, and R&D, production and sales systems covering over 20 countries, becoming one of the global top three.

In just 6 years, Haichen Energy Storage's shipment volume ranked among the global top three. In 2024, Haichen Energy Storage's battery shipment reached 35.1GWh, with a 3-year compound growth rate of 167%. In 2025, it is rushing toward Hong Kong Stock Exchange IPO...

Along with shipment volume, Haichen Energy Storage's revenue growth has also been rocket-like. Its operating revenue rose from 3.615 billion yuan in 2022 to 10.202 billion yuan in 2023, further growing to 12.917 billion yuan in 2024.

According to the "2024 Global Unicorn List" released by Hurun Research Institute, Haichen Energy Storage ranks 270th with a valuation of 25 billion yuan.

Haichen Energy Storage's rapid rise caught CATL's attention in 2023. CATL's lawyer stated at the trial of former employee Zhang Min's non-compete restriction dispute that CATL sued Wu Zuyu for violating non-compete agreements, ultimately resulting in Wu Zuyu's wife Lin Xiuhua paying 1 million yuan in breach penalties on his behalf in September 2023.

In November 2023, CATL's lawsuit against another employee Zhang Min's non-compete agreement dispute went to trial, again involving Haichen Energy Storage.

Zhang Min was a deep cell system engineer at CATL, mainly responsible for power product line planning and development, product development and mass production maintenance. He was also a recipient of CATL's 2018-2021 restricted stock incentives.

At the end of 2021, Zhang Min left CATL and joined Xiamen Rare Earth Materials Research Institute, engaging in electrochemical energy storage and device-related research. However, CATL photographed Zhang Min multiple times wearing Haichen Energy Storage badges entering and leaving Haichen Energy Storage facilities in 2023, believing that while at Xiamen Rare Earth Materials Research Institute, Zhang Min was actually serving Haichen Energy Storage, violating non-compete restrictions, and demanding 1 million yuan in breach penalties.

It's worth noting that Xiamen Rare Earth Materials Research Institute is also listed as a defendant in the unfair competition dispute case that opened on August 12.

At Zhang Min's case trial, CATL's representing lawyer stated, "Wu Zuyu not only violated non-compete agreements himself but also used his work experience and network at CATL to extensively poach CATL's core technical talent, rapidly capturing the energy storage market within two years, causing immeasurable losses to CATL that far exceed what a mere 1 million yuan can compensate."

According to reports, at the end of 2019, Wu Zuyu left CATL to start his business, taking away a group of business backbones including Sun Minghuang, Zhang Wancai, Lu Guangbo, Wang Shiwen, Huang Chengze, Wu Congmiao, and others.

Among them, in a Haichen Energy Storage public account article on November 5, 2021, Zhang Wancai represented Haichen Energy Storage at the signing ceremony and technical seminar between Xiamen Quality Inspection Institute and SGS. Additionally, according to Tianyancha, for patent CN210886191U applied by Haichen Energy Storage on June 30, 2020, the inventors were Zhang Wancai, Feng Junmin, and Wu Tingting.

It's worth noting that Zhang Wancai also participated in CATL's equity incentive plan in 2018.

In addition, Haichen Energy Storage's supervisor He Yong, Haichen Energy Storage's Deputy General Manager of Technology Management and General Manager of Global Solutions Center Yi Ziqi, and Haichen Energy Storage's Deputy General Manager of Market Strategy Management Pang Wenjie all have work experience at CATL.

Among them, Yi Ziqi and Pang Wenjie also received substantial equity incentives at Haichen Energy Storage.

The prospectus shows that from 2022-2024, Haichen Energy Storage granted stock-based rewards to employees, with stock payment compensation expenses as high as 382 million yuan, 33.99 million yuan, and 23.59 million yuan respectively. Among them, Yi Ziqi and Pang Wenjie had the highest stock payment amounts, at 52.24 million yuan and 44.72 million yuan respectively.

Currently, Haichen Energy Storage is at a crucial juncture of its Hong Kong IPO. It submitted its application to the Hong Kong Stock Exchange in March 2025, planning to raise funds for overseas capacity expansion, but has encountered successive "black swan" events after submission: US major customer Powin Energy's bankruptcy led to large order defaults, coupled with unfair competition dispute lawsuits from CATL, subjecting it to strict scrutiny from the Hong Kong Stock Exchange.