We tend to take batteries for granted.
Day after day, we recharge batteries and expect them to work without giving a thought to how they work or to their state of health.
But Akira Yoshino is different. He's one of the pioneers of lithium-ion battery technology.
He says we're still a long way from perfecting the battery—any battery—for autonomous-car use.
The Japanese visionary, who invented a lithium-ion prototype cell in 1985, says the duty cycles expected of self-driving cars—specifically those in ride-sharing fleets—demand more robust batteries.
Those cells must be designed to withstand constant expansion and contraction far better than today's.
Lithium-ion cell and battery pack assembly for Nissan Leaf electric car in Sunderland, U.K., plant
“A car shared by 10 people means it will be running 10 times more,” Yoshino told Bloomberg during an interview in late December. “Durability will become very important.”
This is a tricky requirement as battery R&D simultaneously focuses on both durability and boosting energy density to increase driving range.
That can bring more expansion and contraction cycles, which could mean changing the chemistry in lithium-ion cells to use materials other than carbon for the anode.
Some researchers and analysts have pointed to lithium-titanate chemistries as one possible solution.
“Cars are a completely new application, and we’ll have to wait until we find out what kind of batteries will really be needed,” Yoshino said. “The future of batteries depends on what will happen to the future of the automobile society.”
Bloomberg New Energy Finance predicts some 54 percent of new cars sold will be electric by 2040.