Widespread take up of Electric Vehicles (EV) will depend on several factors regardless of the hype. The first is range. Batteries in all-electric vehicles will have to carry us a couple of hundred miles between charges before they are going to be widely adopted. It’s okay for those living in cities and keen to save the planet but for most people the risk of not quite getting there will outweigh other considerations. So apart from a comprehensive system of recharging stations, batteries will have to achieve much higher storage capacities and quicker charging times. Well Toshiba thinks they have the answer, a newish battery design called the SCiB (Super Charge Battery) based on a lithium-titanate oxide technology they originally developed for laptops and mobiles but which they now have such faith in for cars. They are building not one but two manufacturing facilities at a cost of some US$280m according to the Financial Times.
According to the article, Toshiba has no existing presence in lithium batteries but claims its lithium-titanate chemistry has a number of advantages. Including a lifespan of more than ten years; much lower risk of fire in a crash, reliable output even when low on charge, and the ability to recharge to 90 per cent of capacity in only five minutes. Another report spells out more precisely Toshiba’s claims saying the company demonstrated the battery’s resilience to damage and thermal runaway by driving a nail through one of their SCiB batteries with no explosion or fire. They also claim that the battery will lose less than 10% of its capacity over a 3,000 cycle life, or roughly as many cycles as would be required for a plug-in hybrid with a 10 year/100,000 mile warranty.
The lithium-titanate significance comes into the cathode material. Usually cathodes are made from carbon but Toshiba has been working on a design improvement for the technology that boosts the storage density to 100W/kg, beating the approx 88W/kg of the Chevy Volt. Energy density is a very important characteristic to EV’s because of weight concerns. The Volt’s T-shaped battery is very large and weighs 400lbs (181kg) for 16kWh of energy. As the energy density increases, the less weight you have to carry for a battery pack. A SCiB battery by comparison would weigh 160kgs or 350lbs.
Subject to price, the weight saving, rapid charging (we have seen figures quoted as low as 90 seconds for a recharge – although where you would find a power outlet with such large charging ability is unclear, certainly not via your home circuits) and reliability of the battery even when deeply discharged (which means the car maker can operate on a lower margin of error) Toshiba is probably onto a winner. The SCiB does appear to outperform the competition and in a field where even minor advantages are significant car makers will no doubt be interested. Our concern is that minor changes like this are all well and good but unless price and convenience can be brought closer to the internal combustion engine mass take up of the electric vehicle is still a long way off.