- Graphite bipolar plates are the core structural components of hydrogen fuel cell stacks, accounting for over 60% of the stack volume, over 80% of the weight, and 30-40% of the cost. It is not only the partition plate of the battery cell, but also the flow field plate and current collector plate, responsible for multiple functions such as distributing reaction gases, collecting conduction current, heat and drainage, and mechanical support.
- Why use graphite instead of metal? The working environment of fuel cells is unique - there are acidic electrolytes (proton exchange membranes), high humidity, and alternating redox atmospheres inside. Metal bipolar plates are prone to corrosion in this environment, and the corrosion products can contaminate the catalyst, leading to a decline in battery performance. Graphite bipolar plates have strong chemical inertness, far superior corrosion resistance to metals, good conductivity, and low density, making them the mainstream choice for commercial fuel cells at present.
- Graphite bipolar plates are divided into three categories according to manufacturing processes:
① Pure graphite bipolar plates - made of high-purity graphite through precision milling channels, with the best performance but high cost and long processing cycle;
② Expanded graphite bipolar plate - formed by stamping flexible graphite plate, with low cost but weak mechanical strength;
③ Composite bipolar plate - graphite powder+resin mixed molding, balancing cost and performance, is currently the most mainstream route.
- With the outbreak of the hydrogen energy industry, the graphite bipolar plate market is expected to grow from about 5 billion yuan in 2025 to over 30 billion yuan in 2030, with a compound annual growth rate of over 40%. This is a high growth track with certainty.
