Robert Bosch GmbH and Samsung SDI Co. Ltd. are establishing a joint venture to develop, manufacture, and sell lithium-ion batteries for automotive applications. The joint venture—SB LiMotive Co. Ltd.—will be headquartered in Korea, and will start operations in September 2008, with production beginning in 2010.
In connection with its automotive hybrid project unit, Bosch has established expertise in areas such as power electronics, battery management, electric motors, transmissions, or DC/DC converters. The main focus of Samsung SDI Co. Ltd. is the further development of lithium-ion batteries, which it already produces for a large number of manufacturers of laptops, mobile phones, and power tools.
Bosch and Samsung will each hold 50% of SB LiMotive, and be equally represented on the board of management and on the board of directors.
In 2007, Samsung SDI Co. Ltd. produced 376 million battery cells, in formats including cylindrical, prismatic and polymer types, primarily targeted at consumer and portable applications. Samsung uses different cathode materials such as cobalt aluminium oxide (LiNiCoAlO2, NCA) and cobalt manganese oxide (LiNiCoMnO2, NMC), for different applications.
Last year, Samsung reported work on developing an 8Ah prismatic lithium-ion cell with high current charge and discharge ability targeted for hybrid electric vehicle (HEV) applications. Samsung designed the power type Li-ion cell using manganese-oxide (LiMn2O4) for the cathode material, with carbon material for the anode.
Performance tests showed the specific power of the new cell was more than 2,000 W/kg at 80% SOC. Samsung built a 14.4V battery module with four cells in series and integrated battery management system (BMS). Ten of these modules were connected to create a 144V battery system with discharge power of more than 12.5 kW at 50% SOC.
In a presentation at the recent Advanced Automotive Battery Conference (AABC), Kiho Kim, Principal Engineer, Energy Lab, R&D Center, Samsung SDI discussed steps the company is taking to improve the low-temperature performance of its power cells for HEV applications.
The cell described here was a prismatic 32120 with 5.7 Ah capacity and a voltage of 2.8V-4.2V.
Samsung is also exploring the use of lithium vanadium oxide as an anode material. In another Samsung paper presented at AABC, Sung-Soo Kim, Principal Engineer in Advanced Battery Development, Energy Lab, said that Samsung has shown 18650 format cells using different vanadate formulations and two different types of cathode with capacities of more than 3,000 mAh.
|Predicted 18650 cell performance with vanadium oxide anodes|
|Type A (4.35-3.0V)||Type B (4.35-3.0V)||Type C (4.35-2.75V)|
|18650 capacity [mAh]||3080||3100||3150|
|0.5C average voltage [V]||3.73||3.67||3.53|
|Energy density [Wh/L]||695||688||673|
In addition, the Li1.1V0.9O2 anodes are showing favorable thermal behaviors compared to existing materials, addressing safety concerns.