--- title: "\"China Membrane\" leads the world, ENERGY TECHNOLOGY and the battle for the \"heart valve\" of lithium batteries" type: "News" locale: "en" url: "https://longbridge.com/en/news/281621320.md" description: "ENERGY TECHNOLOGY leads the world in innovation in the lithium battery separator field. As the \"heart valve\" of lithium batteries, separators play a key role in ensuring battery safety and performance. With the increasing proportion of non-fossil energy consumption in China, the safety and reliability of lithium batteries have become particularly important. The year 2026 is a critical period for China to achieve carbon peaking, and the ultra-thin separators produced by ENERGY TECHNOLOGY's smart factories demonstrate China's leading position in new energy materials" datetime: "2026-04-03T08:43:10.000Z" locales: - [zh-CN](https://longbridge.com/zh-CN/news/281621320.md) - [en](https://longbridge.com/en/news/281621320.md) - [zh-HK](https://longbridge.com/zh-HK/news/281621320.md) --- # "China Membrane" leads the world, ENERGY TECHNOLOGY and the battle for the "heart valve" of lithium batteries In early spring 2026, as the National Two Sessions concluded, the blueprint of the "14th Five-Year Plan" became increasingly clear amidst the heated discussions among representatives and committee members. When China's non-fossil energy consumption ratio exceeds 20%, and policies actively promote the development of a green and low-carbon economy, the deeper challenges of energy system transformation also emerge: how to develop and strengthen emerging industries such as new energy, ensuring that green electricity is not only generated but also used effectively and stably? This is not only a challenge for the power grid but also for the lithium battery industry chain. In the "sandwich" structure of lithium batteries, the positive and negative electrode materials must not come into contact; otherwise, it will short-circuit and catch fire. The separator is the key material that physically separates the positive and negative electrodes, allowing only lithium ions to pass through. It does not contribute to energy density but determines the safety baseline of the battery; it is as thin as a cicada's wing yet bears a heavy responsibility. The industry refers to it as the "heart valve" of lithium batteries. At the same time that the world seeks energy transformation, an intelligent factory is quietly operating in Yuxi, Yunnan, located in the central part of the province. Rolls of silver-white film are smoothly transported along a highly clean production line, ultimately becoming lithium battery separators with a thickness of only 5 microns. It is thin enough to be one-twentieth the thickness of A4 paper, yet it can withstand punctures from hundreds of grams of weight without damage. This is the factory of ENERGY TECHNOLOGY and a microcosm of China's transition from catching up to leading in new energy materials. **Between Microns, Heavy Responsibilities** The year 2026 marks the beginning of the "14th Five-Year Plan" and is a critical sprint period for China to strive for carbon peaking by 2030. Currently, the national energy system is working on strategic tasks such as ensuring energy security, green and low-carbon transformation, and building a strong energy nation. Li Chuangjun, Director of the New Energy and Renewable Energy Department of the National Energy Administration, proposed to promote the "14th Five-Year Plan" for renewable energy to achieve expansion and quality improvement, providing reliable alternatives. Behind this is a practical examination: the proportion of "green" in the power system is rapidly increasing, and the safety and reliability of devices such as lithium batteries have never been more important. The role of the separator in lithium batteries deeply resonates with the phrase "reliable alternatives." It not only isolates the positive and negative electrodes to prevent short circuits and fires but also directly affects the battery's energy density and rate performance through its thickness, porosity, and puncture strength. It can be said that without breakthroughs in separator technology, there would be no high energy density power batteries today; it is an indispensable key material in the process of the new energy industry evolving from 0 to 1, and then from 1 to 100. Currently, Chinese separator manufacturers hold nearly 90% of the global market share. In this field, ENERGY TECHNOLOGY has become a global leader. According to SNE Research data, from January to October 2025, ENERGY TECHNOLOGY's market share firmly held the top position globally. "The separator does not contribute to energy density in the battery, but to pack more active materials into a limited space and enhance energy density, we need to continuously make the separator thinner," explained Jiao Lingkuan, Vice President of the Global Research Institute of ENERGY TECHNOLOGY, regarding the underlying logic of the industry Making it thin means challenging physical limits. The thickness of a standard A4 paper is about 100 microns, while the main product of ENERGY TECHNOLOGY has a thickness of only one-twentieth of that. However, extreme thinness cannot come at the expense of safety. The core function of the separator is to isolate the positive and negative electrodes and conduct lithium ions; once it ruptures, the battery can short-circuit and catch fire, with dire consequences. Based on the core indicator of puncture resistance of the separator, ENERGY TECHNOLOGY proposed the concept of "micron thousand jun," where the separator can still withstand hundreds of grams of weight piercing without damage at a thickness of just a few microns. From 9 microns to 7 microns, and then to 5 microns of wet separators, the logic followed by ENERGY TECHNOLOGY has always been to balance thinness, high strength, and fast conductivity. In August 2025, ENERGY TECHNOLOGY officially launched a new generation of 5-micron ultra-thin high-strength separators. Compared to the conventional 7-micron products, the thickness is reduced by 28.5%, but the puncture strength has increased by 16.7%, reaching a puncture strength of 550gf. In 2025, the lithium battery separator industry experienced a rebound after hitting bottom. ENERGY TECHNOLOGY expects to achieve a net profit of 109 million to 164 million yuan for the whole year, turning losses into profits year-on-year. The main products of ENERGY TECHNOLOGY are lithium battery separators, including two major categories: base film and coated film, which have long accounted for more than 80% of the company's revenue. Behind the performance reversal is ENERGY TECHNOLOGY's "three highs and one long" philosophy: high technology, high quality, high efficiency, and adherence to long-termism. In the face of industry price wars, the management of ENERGY TECHNOLOGY has clearly abandoned the short-term thinking of "exchanging price for volume" and implemented a strategy of "differentiated competition + value upgrade." "Industry reshuffling is inevitable; we are not afraid of price wars, but we refuse low-level repetition. The country says that during the '14th Five-Year Plan' we need to 'expand volume and improve quality, and ensure reliable alternatives,' and we take this to heart," said Li Xiaoming, founder and chairman of ENERGY TECHNOLOGY. "For the past twenty years, our mission has been 'from nothing to something, breaking monopolies.' Today, ENERGY TECHNOLOGY's mission has changed to 'from something to strong, leading change.' While others are focusing on thickness, we are focusing on strength, safety, and consistency, making the same products more reliable. This is our moat." **Great Power Membrane Strength: From Catching Up to Leading** Among the four main materials for lithium batteries, the separator is the last to achieve localization and has the highest technical threshold. Why has it become one of the four main materials? How high is the technical threshold for wet separators? According to ENERGY TECHNOLOGY, the technical threshold for wet separators focuses on four dimensions: material formulation, process precision, equipment capability, and consistency control. Coupled with high capital investment and long R&D cycles, new entrants must overcome the full-chain barriers of materials, equipment, and processes, while continuously addressing the challenges of battery technology iteration. First is the base film manufacturing process. From polymer material formulation to biaxial stretching process control, from extraction technology to thermal setting process, every link needs precise control. Second is the design of the microporous structure, where pore diameter must be controlled at the nanoscale (usually 0.01–0.1 microns), and porosity must be between 30% and 50%; too high will reduce strength, while too low will affect ionic conductivity. Third is the coating technology, where the dispersion of materials like ceramics and PVDF, as well as the precision of the coating process, directly affect the functional performance of the separator The fourth is the integration of equipment and production lines. Equipment such as extruders, stretching machines, and extraction tanks need to be customized. Imported equipment from companies like Japan Steel Works and Germany's Bruckner is expensive and complex to maintain. Finally, there is consistency control; the thickness tolerance of high-end membranes must be less than or equal to 1 micron (for example, the actual thickness of a 7-micron membrane should be within the range of 6 to 8 microns). Additionally, factors such as raw material fluctuations and temperature drifts during continuous production can easily lead to performance differences, requiring full online monitoring. Each of these hurdles is enough to block the vast majority of new entrants, but ENJIE has overcome them one by one. Looking back, the growth history of ENJIE Co., Ltd. is also a story of breakthrough in China's manufacturing industry. "To be honest, there are still times late at night when I think back to the early days of making membranes," said Li Xiaoming. "Membranes may look like a layer of plastic film, but they involve polymer materials, nano-channel formation, and precision coating, making it an extremely complex science. When we first debugged the equipment, many members of our team lived and worked in the workshop for months." To produce world-class membranes, it is this belief that supports the ENJIE team in maintaining the determination of "sitting on a bench for ten years." From material formulation to biaxial stretching processes, from pore size control to breakthroughs in coating technology, ENJIE has gradually conquered the technical barriers of wet-process membranes. Today, ENJIE Co., Ltd.'s R&D is undertaken by its global research institute located in Shanghai, with a team of over 500 people from countries including China, the United States, Japan, and South Korea. It has established institutions such as the Institute of Advanced Technology Research, Product Development Center, and Process Technology Development Institute, covering the entire chain of materials, processes, equipment, and testing. As of February 2026, ENJIE Co., Ltd. has accumulated 512 authorized patents, including 51 international patents, with another 318 pending. The annual R&D investment is approximately 700 million yuan. ENJIE Co., Ltd. places great importance on talent team building and continuously excavates and cultivates potential talents from within. By 2025, several key personnel have been promoted to critical positions in production bases and functional departments at headquarters, injecting new vitality into the organization. Leveraging the group's advantages of multiple bases and businesses both domestically and overseas, ENJIE Co., Ltd. has created diversified development paths for employees across fields and regions, broadening their career growth space and enhancing the organization's resilience and collaboration. Through a dual-driven approach of "internal training and external recruitment," ENJIE Co., Ltd. has built a talent echelon with a reasonable structure and diverse capabilities, providing talent support and intellectual assurance for promoting high-quality business development. At the ENJIE base in Yuxi, Yunnan, scenes of workers densely shuttling through traditional manufacturing are almost invisible. Instead, there are automated devices operating in a highly clean environment. This is an intelligent production base designed based on ENJIE Co., Ltd.'s "lighthouse factory" model, adhering to the highest standards of Industry 4.0. At its core is a digital "super brain," where engineers only need to operate computers in the control center to monitor and allocate production data and rhythms across the entire production line in real-time. Behind the digital management, ENJIE Co., Ltd. has undergone digital transformation in various aspects such as R&D, production, supply chain, sales, and services, constructing a commercial intelligence analysis report covering procurement, inventory, production, and finance. Through 147 indicators, it manages issues through data analysis, promoting the entire staff to form a work habit of "data-driven decision-making." ENERGY TECHNOLOGY believes that "the new productive forces in the diaphragm industry are driven by technological innovation, characterized by green and low-carbon principles, supported by intelligent manufacturing, and guided by global collaboration, promoting the industry's leap towards high quality, high resilience, and high added value." **Crossing Cycles, Leading the Future** As the global leader in diaphragms, ENERGY TECHNOLOGY does not rest on its laurels. In December 2021, ENERGY TECHNOLOGY established Hunan ENERGY TECHNOLOGY Frontier New Materials Co., Ltd. (hereinafter referred to as "Hunan ENERGY TECHNOLOGY"), officially entering the field of solid-state battery materials. ENERGY TECHNOLOGY chose the sulfide route, which has the greatest potential, as sulfides are considered the mainstream path for solid-state batteries due to their ultra-high ionic conductivity and good processing performance. Leading companies such as Toyota from Japan, LG from South Korea, and domestic firms like CATL, BYD, Zhongxin Innovation, and Guoxuan High-Tech have all made arrangements in this area. In the face of solid-state battery technology, which is hailed as "the next generation battery," there are many "disruption theories" both inside and outside the industry, with some worrying that the popularization of solid-state batteries will render the diaphragm industry obsolete overnight. ENERGY TECHNOLOGY's stance is very clear: "Semi-solid still requires diaphragms, and full solid-state still needs time. Semi-solid batteries still use diaphragms, and ENERGY TECHNOLOGY's related products have been supplied in bulk to leading companies like Weilan New Energy; the scaling and industrialization of full solid-state batteries will still take a long time, and it is expected that before 2030, they will mainly be applied in high-end niche fields such as deep space and deep sea, and will not disrupt the existing diaphragm market in the short term." Li Xiaoming stated, "A true industry leader must dare to undergo self-revolution, which is why we started researching solid electrolytes and lithium sulfide early on. If we really enter the solid-state era in the future, ENERGY TECHNOLOGY still aims to be a core supplier in this field. Our vision has never been just to hold onto a piece of diaphragm, but to become a globally leading new energy materials company." Currently, Hunan ENERGY TECHNOLOGY's high-purity lithium sulfide product has completed the construction of a 10-ton pilot line, and the product has been recognized by leading customers, achieving small batch shipments of high-purity lithium sulfide. The 10-ton production line for solid electrolytes has been put into operation and has the capacity for ton-level shipments, with new electrolyte products sent to leading battery companies both domestically and internationally for sampling. In terms of electrolyte membranes, ultra-thin and high-toughness products are in the research and sampling stage, with conductivity and other indicators at the industry-leading level. ENERGY TECHNOLOGY has reached strategic cooperation agreements with Weilan New Energy, Guoxuan High-Tech, and Enli Power. In 2025, ENERGY TECHNOLOGY signed a procurement framework agreement with Beijing Weilan New Energy, agreeing on procurement shares for 2025-2030; and signed an agreement with Enli Power to jointly develop high-performance electrolyte diaphragms suitable for solid-state batteries. Forward-looking technological layout ultimately needs to translate into a global market landscape. In ENERGY TECHNOLOGY's view, true industry leaders must not only define the future in technology but also occupy a core position in the global industrial chain. In the face of an increasingly complex international trade environment, ENERGY TECHNOLOGY's strategy is "local service for globalization," using localized production capacity, teams, and services to deeply integrate into the global market. Currently, ENERGY TECHNOLOGY's globalization layout has begun to take shape. Its U.S. base project is steadily advancing; the Hungarian base has reached cooperation with local leading companies and has begun supplying overseas customers. By employing local teams and strictly adhering to local regulations, ENERGY TECHNOLOGY will ensure the steady development of its overseas business From a local enterprise in Yuxi, Yunnan, to a global leader in the diaphragm industry, ENERGY TECHNOLOGY officially entered the lithium battery diaphragm sector in 2010 under the leadership of Chairman Li Xiaoming. After 16 years of hard work, it has grown from one diaphragm factory to currently 13 diaphragm factories, expanding from China to the world, increasing the market share of domestic diaphragms globally from 4% to over 93%, becoming a leader in the global lithium battery diaphragm industry. The journey of ENERGY TECHNOLOGY is a model of the rise of China's new energy industry chain. In Li Xiaoming's view, "Letting more new energy vehicles use safe and stable ENERGY TECHNOLOGY diaphragms is not only a business but also our generation's mission and responsibility for global sustainable development." 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