Breakthrough battery could double bus range
A German battery technology company says it has set the bar for energy density with its latest lithium ion system.
AKASOL, based in Darmstadt, near Frankfurt, is claiming 220 Watt hours per kilogram (Wh/kg) for its battery, beating the lithium ferrous phosphate (LFP) technology adopted by many bus manufacturers. In an exclusive interview with Bus & Coach Buyer, AKASOL’s CEO, Sven Schulz, said drive system manufacturers are usually faced with a trade-off with LFP, which he says cannot be truly fast-charged but have the advantage of a long service life.
“When we started, the disadvantage of the nickel manganese cobalt [NMC] battery chemistry we were using was a cycle life [to 80% capacity] of 1,000 cycles, so we decided to start developing the technology with our cell supplier in Korea,” he told BCB.
“We can now achieve 3,000 cycles. Typically, LFP batteries achieve an energy density of 120 to 130Wh/kg. Now, we can achieve 220Wh/kg.” Sven said the system could “easily achieve 600 to 1,000kWh” aboard a heavy vehicle, and has a target range of 600km which, he says, is now feasible.
The AKASOL technology has already found favour with Daimler, and an unnamed Swedish bus and coach builder, with the second generation system becoming available next year. He said that, as yet, no British bus builder is working with AKASOL.
While most battery technology is sourced in China, Sven said AKASOL had met barriers to trade with NMC chemistry, and had instead worked with a manufacturer in South Korea. The development had sought engineering solutions for a complete, liquid-cooled battery module with self-management capability.
“Of course, any battery must be competitive in terms of cost, and we believe we can achieve the cost values expected,” he told BCB. He added that ruggedising the module and ensuring complete fire safety had been at the core of development. Although buses and coaches would, ideally, be built around the battery technology it is feasible that they could be adapted to existing electric power drivelines.
Sven said the Holy Grail of battery technology would be solid-state lithium, which would eliminate the possibility of leakage, but he estimates that production may still be ten years or more away.