Researchers at Toshiba continue development on next-generation SCiB lithium-ion batteries, which could replace the current LTO chemistry used in ultra-fast charging applications (in 5-15 minutes).
According to an article in the Journal of Power Sources, the new titanium niobium oxide – TiNb2O7 (TNO) composite anode consisting of micro-size spherical TNO secondary particles coated with carbon, combined with standard NCM, is very promising.
The prototype TNO/NCM cell (49 Ah) doubled the volumetric density of LTO, while still maintaining the ultra-fast charging capability and long cycle-life.
Here are some numbers:
- 49 Ah capacity
- 350 Wh/L volumetric energy density
- high input-power density of 10 kW/L for 10 s at 50% state of charge (SOC)
- 0% to 90% SOC in less than 6 min
- capacity retention at 7000 cycles was 86% by full charge-discharge cycling at 1C rate
- cycle-life was predicted to be 14000 cycles
- There is no data on gravimetric energy density Wh/kg, but we wouldn’t expect anything on par with high
- energy density cells for long-range BEVs.
At 350 Wh/L TNO, is still far behind, although in all application with ultra-fast charging like some electric buses, it could represent a major improvement.
“Electrochemical properties of TiNb2O7 (TNO) electrodes during lithium storage have been studied in order to develop an alternative anode with high-capacity, fast-charging, and long-life to Li4Ti5O12 (LTO) in lithium-ion batteries. High-density TNO (HD-TNO) composite electrode consisting of micro-size spherical TNO secondary particles coated with carbon exhibited high-rate capability, long cycle-life, and a high volumetric capacity of more than twice that of LTO composite anodes. Large-size lithium-ion batteries using the HD-TNO anode and a LiNi0.6Co0.2Mn0.2O2 (NCM) cathode with a capacity of 49 A h were fabricated for automotive applications, and were found to have a high energy density of 350 W h L−1, a high input-power density of 10 kW L−1 for 10 s at 50% state of charge (SOC), and fast-charging from 0% to 90% SOC in less than 6 min. The capacity retention at 7000 cycles was 86% by full charge-discharge cycling at 1C rate. Cycle life was predicted to be 14000 cycles at 80% capacity retention. It was demonstrated that the TNO/NCM batteries have high energy-density, fast-charging, and long cycle-life for automotive applications such as electric vehicles with long driving ranges by fast-charging.”