German automotive provider Schaeffler has launched a brand new era of bipolar plates for PEM gasoline cells. The plates’ design is optimised for large-scale manufacturing, they usually use a brand new coating course of for a very lengthy service life.
In keeping with Schaeffler, stacks geared up with these plates additionally obtain an influence density of round 20 per cent larger than stacks with the plates of the earlier era. Schaeffler is at the moment producing the plates for prototypes and small sequence for automobile producers on a pilot plant in Herzogenaurach. From the start of 2024, the bipolar plates will probably be manufactured within the Innoplate three way partnership, based with Symbio in Haguenau, France, in considerably bigger portions.
Bipolar plates have an essential perform within the gasoline cell: they separate and distribute the method gases and the coolant and take away water produced by the chemical response. The optimisation is especially about making the plates smaller and lighter whereas bettering the properties for the precise job. For a gasoline cell stack for autos, a number of hundred bipolar plates and membrane electrode items (MEA) are alternately layered on prime of one another. On this composite, the plates account for as much as 80 per cent of the stack weight and as much as 65 per cent of the stack quantity. In keeping with Schaeffler, as much as 400 such cell composites are stacked for a 140 kW stack.
“Schaeffler has developed an modern design that makes optimum use of the plate’s floor space,” says Jochen Schröder, head of the E-Mobility division at Schaeffler. “The finer and extra exact the constructions on the bipolar plate, the extra environment friendly the plate is.” In keeping with the press launch, that is how the provider achieves an influence density of 4.6 kilowatts per litre for the gasoline cell stack, primarily based on the stack quantity, together with the top plates and the bracing.
Nevertheless, “the finer and extra exact the constructions on the bipolar plates”, the extra complicated the manufacturing often turns into. Right here, Schaeffler has “designed from the bottom up for industrialisation at massive scale – an method often known as design for manufacturing (DFM).” Mixed with the corporate’s metallic stamping and forming experience, effective constructions can thus be embossed on 50 to 100-micrometre thick plates even in large-scale manufacturing processes.
Along with manufacturing and vitality density, Schaeffler sees the coating system as “one other distinctive characteristic.” The provider has developed a number of high-performance coating programs for bipolar plates, which – relying on the client’s needs – are geared toward significantly excessive service life necessities, the bottom doable CO2 footprint or an optimised price-performance ratio. The coating programs are utilized utilizing the bodily vapour deposition (PVD) course of, which has been adopted from the manufacturing of extremely pressured valve prepare parts, confirmed thousands and thousands of instances over, and refined even additional.
“Due to our capabilities in floor know-how, we’re capable of provide every buyer an application-specific coating resolution. This implies we will meet every buyer’s necessities by way of balancing value, efficiency, and manufacturing-related CO2 emissions,” says Schröder.
schaeffler.com