Toshiba Batteries Main Features and Optimization (Part II of III)

Click here if you missed the previous parts of this article: part I

Battery Lifetime Data

Toshiba’s SCiB™ battery has undergone significant amount of testing that assures its performance and capability over the entire lifetime. The SCiB™ provides a capacity recovery rate of over 80% after 10,000 charge-discharge cycles with the full SOC range (0-100%) as shown in Figure 5. Moreover, if SCiB™ is used within a limited SOC range, outstandingly long cycle life (or almost no degradation) will be expected as shown in Figure 6.

Figure 5: SCiB™ 20Ah cell Charge/Discharge Lifecycle (SOC 0-100%, 3C)

Figure 6: SCiB™ 20Ah cell Charge/Discharge Lifecycle (SOC 50-90%)
(Upper: 1C, Lower: 3C)

Calendar Life of SCiB™ Battery at 90% SOC and Minimal Cycling

Toshiba’s SCiB™ has undergone recovery discharge capacity test at 90% SOC, 35°C and minimal cycling. The SCiB provides a capacity recovery rate of about 98% after 600 days as shown in Figure 7.

Figure 7: SCiB™20Ah cell at 90% SOC, Minimal Cycling at 35°C

Given that the test temperature in Figure 7 is more severe than the requirement (20°C to 25°C), it is expected to have a better performance at 25 °C.

Chemical Composition of the SCiB™

Compared to other battery chemistries, the SCiB™ has a very high performance and safety level due to the advanced materials and chemistry used in the battery. The chemical composition of each cell consists of (Refer to Appendix B for the Product Safety Data Sheet):

Chemical Name	Weight percentage%
Complex oxide positive active material including lithium, nickel, and the other elements	22-32%
Lithium Titanate	22-32%
Electrolyte solvent (main components are cyclic and linear carbonates)	10-20%
Electrolyte salt (Lithium salt of fluoro-complex compound)	Li in electrolyte: 0.1-0.2 F in electrolyte: 1.5-2.5

Comparison with Other Battery Technology

With this advance technology, the SCiB™ offers superior capability in 4 major areas: Energy Density, Lifetime, Operational Temperature and the Speed of Charging. The table below shows the comparison between the SCiB™ and other battery chemistries:

Figure 8: Comparison between different battery chemistry

Temperature Dependencies

SCiB™ provides sufficient discharge capacity at various temperatures ranging from ice-cold -30℃. This makes SCiB™ suitable for applications over a wide range of temperature.

Figure 9: SCiB™ provides sufficient discharge capacity at various temperatures

Charge Characteristics of the Battery Cell

In automotive, the amount of time spent in charging the vehicle is a critical factor. In this case, the SCiB™ is capable to operate at high C-rates, significantly reducing the amount of time spent charging.

Figure 10: Rapid charge of battery to 80% SOC in 6 mins

The SCiB™ battery technology delivers:

Fast charge rates (80% charge in 6 minutes).
High input/output power densities, comparable to capacitors.
Safe operation due to lower operating temperature and increased thermal stability.

Written by Fabio Muzio, from Toshiba