Toshiba is developing a rechargeable lithium-ion battery with a niobium-titanium oxide anode and has now started to deliver cell samples to manufacturers. The ‘SCiB Nb’ is said to be similar to LFP cells in terms of volumetric energy density, but has clear advantages in terms of fast charging and service life.
Toshiba wants to position its lithium-ion battery with a niobium titanium oxide anode as an alternative to today’s widely used Li-ion batteries with a graphite anode, particularly in the commercial vehicle market. LFP batteries also belong to this category. According to Toshiba, the anode made of niobium titanium oxide (NTO) instead of graphite gives the battery a volumetric energy density that is comparable to LFP batteries, but it should be better able to withstand repeated, faster charging. Specifically, the developers claim an 80 per cent charge in ten minutes for the ‘SCiB Nb’. Even with repeated fast partial charging, it should have an estimated service life of 15,000 cycles.
Toshiba is working closely with two strategic partners to develop its new battery: the Brazilian company CBMM, one of the world’s largest producers of niobium, and the Japanese Sojitz Corporation, one of CBMM’s shareholders and CBMM’s sole representative for the Japanese market, where the company “built a stable niobium titanate supply system and cultivates applications, and is now ready to bring this rapid-charging, long-life product to market,” according to Toshiba. The partnership is initially aimed at use in commercial vehicles, where high availability and dense operating cycles are important. “Frequent charging at designated points along the route allows reductions in number of installed batteries, while long-life performance is expected to lower the total cost of ownership by decreasing the need for frequent battery replacements due to degradation,” Toshiba advertises.
The samples now ready for delivery are specifically 50 Ah cells with a nominal voltage of 2.3 volts and an output power of 1 kW. Toshiba puts the volumetric energy density at 350 Wh/L and the gravimetric energy density at 130 Wh/kg. The cell measures 98 x 280 x 12 millimetres and weighs around 860 grams. The Japanese company specifies a charging capacity of 5C, which corresponds to a ten-minute charge to 80 per cent SoC. The operating temperature is said to be between -30 and +60 degrees.
Toshiba also explains in more detail why batteries with NTO anodes are said to be superior to current graphite-based lithium-ion batteries, especially LFP batteries: Although these could provide the required energy density, repeated rapid charging leads to lithium deposits on the anode, “which increases the risk of a short circuit in the cell, especially when the batteries start to degrade.” According to Toshiba, the NTO anode, on the other hand, does not cause metallic lithium deposits and should be safe to use for a long time even with repeated fast charging. An initial trial with an electric bus prototype is said to have already taken place: Toshiba claims to have already trialled its new battery development in a vehicle at the CBMM industrial plant in Araxá, Brazil.
In addition to the ‘SCiB Nb’, Toshiba has already commercialised a cell called ‘SCiB’. This is a lithium-ion cell with a lithium titanate anode.
global.toshiba
