Sumitomo considering marketing new lower-temperature molten-salt electrolyte battery to automakers for EVs and hybrids
|Construction of the molten-salt electrolyte battery. Source: Sumitomo. Click to enlarge.|
Sumitomo Electric Industries Ltd. is considering targeting its lower-temperature molten-salt electrolyte battery, being developed in partnership with Kyoto University (earlier post), to makers of electric and hybrid passenger cars, according to Bloomberg.
Sumitomo had earlier said that it intended to commercialize the battery around 2015 for commercial-vehicle fleet operators and stationary applications, and was targeting revenue of more than ¥1 trillion (US$13 billion) from it.
Being non-volatile and non-flammable, and with high ion concentrations, molten salt makes an excellent battery electrolyte and can offer high energy and power densities; Sumitomo earlier reported that it has achieved energy densities as high as 290 Wh/L with the new battery. A drawback to the general class of molten salt batteries (e.g., the ZEBRA battery, or GE’s Durathon sodium-metal halide batteries, earlier post) has been the need for high operating temperatures to keep the salt molten.
In a joint project with Kyoto University, Sumitomo developed a molten salt with a melting point as low as 57 °C. Using this salt, it developed the new molten-salt electrolyte battery.
Since it comprises only nonflammable materials, the new battery will not ignite on contact with air from outside, nor is there thermal runaway from overcharging or temperature rises in the battery. For this reason, Sumitomo says, there is no need for waste-heat storage or fire- and explosion-proof equipment, so the batteries can be packed close together.
The company earlier reported that based on its trial calculations, assuming equal capacity, the new battery had half the volume of lithium-ion batteries and one quarter that of sodium-sulfur batteries, enabling miniaturization.
Sumitomo is continuing work on the battery to find molten salt that can be used at still lower temperatures.
Sumitomo Electric Annual Report 2011