Bipolar plate is the core part of fuel cells, liquid flow batteries and other energy storage battery stacks. The technology of graphite and metal bipolar plates developed earlier in Europe, America and Japan, and United States and Britain are in pole position in field of composite bipolar plates. At present, most of the bipolar plate manufacturers mainly produce graphite bipolar plates in China. Some indices of graphite bipolar plates developed by some domestic suppliers have reached the world advanced level. With the commercialization of fuel cell vehicles driven by Chinese government, It’s believed that the market scale of bipolar plates will be further expanded.

Status of bipolar plate suppliers in China

In China, graphite bipolar plates are still the mainstream of the market, account for about 50% of total scale. The metal bipolar plate has a share of approx. 40% after rapid growth. Graphite bipolar plate materials include artificial graphite and natural graphite. The processing technology includes molding and machining, the machining technology is still popular for graphite bipolar plate production. The metallic bipolar plate has advantages of high efficiency and high mechanical strength, which can meet the requirements of large-scale production of fuel cells. Therefore, many stack factories have laid out metal bipolar plates for the future, and the market share has also increased year by year. The common materials of metal bipolar plates in China include titanium, aluminum, nickel, stainless steel, etc., which are based on self development. Besides, stamping and coating process can be carried out via outer factories according to needs.

From the supplier’s location, graphite bipolar plate enterprises have a wide distribution in China, and East China has the largest number of bipolar plate factories, and that’s where the production is most concentrated for graphite and metal bipolar plates in China. With the progress of coating technology, the performance of corrosion resistance for metallic polar plates is continuously improved. The number of metal polar plate suppliers in China is also increasing year by year. In addition, some battery stack manufacturers will also engage in the production of polar plates to improve their own competitiveness, integrate core components such as bipolar plate and membrane electrode to gradually form a closed loop industry chain for fuel cell or liquid flow battery.

Problems in chinese bipolar plate manufacturers

At present, the technical difficulties for China bipolar plate manufacturing mainly focus on the channel design, coating treatment, molding, welding, sealing and others. The graphite electrode plates have issues such as oversize volume, poor mechanical strength and processability. The metal electrode plates have high power density but poor corrosion resistance. The composite electrode plates is difficult for processing, and hard to control the overall cost.

Graphite bipolar plate manufacturers are mature in technology and market, and occupy a large market share in China. So it’s difficult to further reduce costs through large-scale production, and we can only look forward to technological breakthroughs in upstream graphite materials. Generally, the cost of graphite materials only accounts for 20% of total cost, while the processing cost can reach approx. 80%. Due to the brittleness of material, the thickness of graphite electrode plates are generally 2 to 4mm, then the flow channel is formed through machining process. The flow channel design and processing technology can both affect the performance of battery stack. Metal bipolar plates have advantages in space utilization because they can be made very thin, but the short service life caused by poor durability has seriously restricted the large-scale application in energy storage industry. Popularly, corrosion-resistant materials are coated on metal plate surface for protection in the foreign country, in terms of coating technology research, there is still much room for improvement in China. In addition, if the output of metal plates is too low, the unit coating cost will remain a high level, which will further push up the overall cost of metal polar plates. For composite bipolar plate, the cost of metal-based materials is very high due to its complicated structure and complicated processing requirements, result in its slow development. Through optimizing the composition and proportion, Carbon-based polymer bipolar plates can realize mass prodution, and the electrode materials can meet the performance requirements of PEMFC, which is favored by most of graphite polar plate manufacturers.

Development of bipolar plate factory in China

As a mature component for fuel cell stack, graphite polar plates have been basically localized in China. Domestic bipolar plate factories still have room for improvement in lightness, large area, high strength and processing technology in the future. It’s expected to occupy a large market share in area of commercial vehicles for a long time. At present, the production capacity of metal polar plates has a tendency to approach and surpass that of graphite polar plates. After overcoming the durability issues through research and development of coating technology, it’s regarded as a good solution for large-scale mass production. It’s deduced that the number of fuel vehicles will reach one million in the next ten years, the huge market potential in the field of passenger vehicles has attracted a large number of chinese manufacturers from various industries. The future research for carbon-based composite bipolar plates will focus on the selection of polymers, conductive fillers and additives to ensure good electrical and mechanical properties.

As hydrogen fuel-cell vehicles enter a new development stage, the requirements for fuel cell bipolar plates in China will also enter into the fast lane. In recent years, the chinese polar plate manufacturers tend to increase production capacity, and the total supply has exceeded 20 million pieces. The intensified market competition will also promote the continuous breakthrough on new technologies and new processing technology, to overcome technical barriers. As a professional China supplier for bipolar plate materials, Nanjing xuneng Hanyuan new materials Co., Ltd.(XNHY) has been deeply engaged in the energy storage industry for many years, and provide high-quality products and services with best price for chinese and foreign manufacturers in areas of liquid flow batteries and fuel cells.