【Ten Years of Rapid Development in Chemical Engineering Equipment】From 1259 to 2023: Self-developed Type IV hydrogen storage tanks achieved a hydrogen storage density of over 6.1 wt%
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The high-quality storage of hydrogen at high density is a crucial technical barrier that must be overcome to enable the commercial use of hydrogen energy; it directly affects the efficiency, cost-effectiveness, and viability of hydrogen fuel cell vehicles. Recently, significant progress has been made with the second-generation 70MPa-57L Type IV hydrogen storage tanks developed independently by Weishi Energy. The mass hydrogen storage density achieved is 6.1 wt%, which exceeds the target value of 5.5 wt% set by the U.S. Department of Energy (DOE) for 2025, and is also better than the performance metrics of similar products from leading brands in the international market – placing it at a world-leading level. These tanks are primarily suitable for use in hydrogen fuel cell vehicle hydrogen storage systems. At the same time, in line with the application requirements of different market scenarios and customer types, the product planning for Unishine Energy’s Type IV hydrogen storage tanks is being advanced concurrently. These tanks are designed to operate at pressures of 35 MPa and 70 MPa, and come in various specifications such as 70 MPa–23 L and 35 MPa–210 L. Some of these commercial vehicle-mounted Type IV hydrogen storage tanks achieve a hydrogen storage density of 6.8 wt%. All products in this series feature 100% autonomy in terms of key core technologies; the key raw materials (such as carbon fiber) as well as the essential components (such as valve fittings and inner liners) are all domestically produced, which results in a 20% reduction in overall costs. These tanks offer advantages such as light weight, long lifespan, and high safety. They will be launched soon, and customized product development is also available. They are suitable for use in a wide range of applications and fields, including fuel cell-powered passenger vehicles, commercial vehicles (heavy trucks, buses, cold chain logistics vehicles), and ships. During the development of Type IV hydrogen storage tanks, Wei Shi Energy took into account the varying application requirements in different operational environments of its clients, as well as the unique properties of hydrogen as a medium and the functional and structural characteristics of hydrogen storage systems. By leveraging its strengths in research and development of key technologies in this field, and through numerous feasible design options and experimental validations, the company focused on the use of \"new materials, new technologies, and new processes\" to overcome various key technical challenges associated with Type IV hydrogen storage tanks.
While the selection of new materials is indeed important, achieving true stability, consistency, and suitability in the quality of hydrogen storage tanks necessarily relies on scientific structural design. The metal valve seat at the bottle mouth, together with the connector structure of the valve, eliminates the conventional complex multi-component design; through innovative designs for the inner tank, valve seat sealing mechanism, and interface design, an integrated \"direct connection\" is achieved. The metal valve seat features a lightweight structural design, with its outer curves seamlessly connecting to those of the tank’s head. The interaction between the valve seat and the carbon fiber composite material under external impacts is taken into full consideration, ensuring anti-slip and anti-rotation properties. By using finite element analysis software, an optimal \"lightweight\" design is achieved within a scientifically determined safety margin; as a result, its weight is 40% lower than that of competing products. Additionally, an innovative high-performance \"sealing\" solution is employed, which reduces the risk of hydrogen leakage and penetration, thereby further enhancing the product’s safety. Furthermore, in terms of carbon fiber layup design, scientific design methods such as genetic algorithms and simulation software are employed to optimize the winding angle and layup sequence, thereby maximizing the strength and toughness of the carbon fiber prepregs and ensuring the compressive strength and reliability of the hydrogen storage tank throughout the entire operational life cycle of hydrogen fuel cell vehicles.
By leveraging the selection of new materials and the design of new structures, Weishi Energy has boldly innovated in the design of its entire production process. In terms of tank forming technology, it employs an injection molding-welding process that is rarely used in China, thereby achieving a high level of uniformity in tank thickness and dimensional stability within the industry. ▲ Schematic diagram of dry winding. Meanwhile, by adopting a novel \"dry\" winding process using prepreg strips, the coefficient of variation in the product’s performance parameters can be kept at 2-3%. The winding efficiency is increased by over 80% compared to the wet method, while the curing time is reduced by 30%. The fatigue test life exceeds 44,000 cycles. This approach not only helps achieve the goal of weight reduction but also ensures optimal utilization of carbon fiber strength, as well as consistency in burst strength and pressure cycle life. It effectively addresses key issues such as wrinkles and buckling in the internal structure, thereby significantly improving the quality, hydrogen storage density, and production efficiency. Moreover, there is no glue dripping or leakage during the winding process, resulting in a more favorable production environment. This provides solid data support and operational experience for future large-scale production and market supply. At present, the second-generation Type IV hydrogen storage tank series independently developed by Weishi Energy has successfully completed various key testing procedures such as fire tests, durability tests, and performance tests. The construction of the production line is nearing completion, and the work related to the \"three new\" evaluation is being carried out in an orderly manner. This is yet another significant scientific and technological achievement by Weishi Energy in the field of hydrogen storage and transportation, as the company focuses on this area and takes \"bottleneck\" technologies as a starting point for innovation. Following the development of 70MPa hydrogen storage valves, this achievement represents further progress in hydrogen storage technology; it shows that Weishi Energy now possesses the capabilities to design, develop, and manufacture the key components and technologies required for complete hydrogen storage systems, ranging from product development to actual application. This will enable the company to expand its operations across both the supply side and the application side of the industry chain, thereby meeting the growing demand for high-pressure hydrogen storage and transportation solutions. It also allows Weishi Energy to offer its clients more professional, higher-quality, and cost-effective solutions, contributing to the acceleration of the localization of hydrogen storage equipment and opening up new opportunities for cost reduction and efficiency improvement.