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has the potential to provide both ultra-fast charging and high energy density at the same time. We see good performance at the cell level but still have a lot to do to realize it at vehicle level, such as developing the high- performance cooling system.”
Recycling batteries is obviously manda- tory, as Origuchi pointed out. Renault is working with a recycling company to develop the recycling process for EV batteries. The current European direc- tive requires that at least 50% of the weight of the battery be recycled. In the future, rare metals such as nickel, cobalt, and lithium will be recycled at a certain percentage level.
“Technically speaking, it is possible to recover the metals, but the chal- lenge for us is to obtain enough purity to recycle them into our battery again,” said Origuchi. “It is also a tradeoff with the cost of such a recycling process. Typically, the current recycle cost of lithium is much higher than the lithium market price, for example. Recyclability
is one of the priorities when we decide the material choices in our battery.”
The key phrase for battery industry pol- icy is life-cycle assessment (LCA). “We have to take care of the entire manufac- turing and supply chain, starting from the metal mines [and progressing to] material processing, cell and battery manufacturing, in-the-vehicle life as well as second-life usage, and, at the end, recycling,” said Origuchi. “We have to minimize the environmental impact on the whole life cycle of our batteries. It means that the best [solution in terms of] cost might not always be the best solution from an LCA point of view.”
There are several challenges to over- come in ensuring long EV lifetimes, and the industry has a very small window of time in which to do so. As Origuchi pointed out, the first is to improve bat- tery life further, and the second is to perform life-cycle tests to validate a long lifetime. “Recently, we recovered the battery from a customer who drove his ZOE more than 300,000 km, and we
found that the battery degradation level was consistent with our estimation,” said Origuchi.
“With the current technology level, I have to say that we cannot simply replace the [internal combustion engine] cars with EVs, as the battery capacity is still lim- ited — and it should be limited, from an LCA point of view; we cannot have 100 kWh for everybody — and the charging time is much longer than the gasoline-filling time,” he added. “As an engineer, of course, [I would say that] we have to improve our batteries much more — including any breakthrough technology, such as all-solid–state batteries — but maybe we also have to change our mind and our habits by introducing a new transportation sys- tem to our society.”
Maurizio Di Paolo Emilio is editor-in-chief of Power Electronics News and EEWeb.
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