- Home
- About the Group
- Management Plan
- Seven Next-generation Growth Businesses
- Li-ion Battery Materials for HEVs
Harnessing the strengths of the Mitsubishi Chemical Holdings Group
The world's only supplier of all four key materials of lithium-ion batteries
The lithium-ion battery ("LIB") is a type of rechargeable battery in which lithium ions in the electrolyte transfer back and forth between the cathode and the anode. Lithium ions move from the cathode to the anode during charge and from the anode to the cathode during discharge, allowing for repeated use. The average voltage of a LIB is three times more than Ni-Cd and Ni-MH batteries, which were considered mainstream rechargable batteries until now. Providing a lighter, smaller unit with higher voltage, LIBs are rapidly growing in popularity for use in notebook PCs, mobile phones and digital cameras.
Although Ni-MH batteries were used in hybrid electric vehicles (HEVs) in the past, lighter and smaller LIBs are seen as the battery of choice for the next generation. In addition to regular HEVs, LIBs are expected to expand into plug-in HEVs and electric vehicles (EVs).
LIBs contain anode material, cathode material, separators and electrolyte as the key materials. In the case of cylindrical battery cells, cathode, anode, and separator are wound and filled with electrolyte. Mitsubishi Chemical has been dealing with electrolyte and anode material for over 20 years, and began production of cathode material in 2005. Our superior organic synthesis technology, combined with a diverse range of additives, allows us to produce electrolyte with optimum performance specific to each type of battery. We currently hold 25 percent of the market share for electrolyte.
In anode material, our technology allows us to control the diameter, shape and surface area of carbon particles (the raw material of the anode), enabling us to meet the increasing need for higher power output and larger capacity. Our cathode material consists of a composition suitable for high power output devices such as motor vehicles, and minimizes the content of high-priced cobalt. By producing cathode material from a metallic oxide called lithium cobalt oxide, cobalt content is minimized and costs are reduced.
The separator component separates the cathode and anode while maintaining conductivity between the two. It also maintains safety by shutting down if excess heat is generated. Lithium ions travel back and forth through tiny holes in a plastic film, which is the base material of a separator. Mitsubishi Plastics began development of separators in 2003, and started working on development with Mitsubishi Chemical in 2006. Together, the two companies created an innovative dry production process, based on several years of material planning and film-forming technology. The Mitsubishi Chemical Holdings Group is the only organization in the world to provide electrolyte, anode material, cathode material and separators − all four key materials of the LIB.
Mitsubishi Chemical has spent many years evaluating and analyzing these components both separately and in a combined form, and our accumulative technology is highly regarded by users.
Automotive manufacturers and battery manufacturers are now joining forces in various ways, competing to develop LIBs for vehicles. Although a small number of LIB-powered vehicles have started to reach the market, full-scale expansion of LIBs is still to come. Apart from the obvious need for high power output, LIBs for vehicles require a much higher level of durability and safety compared to LIBs for mobile phones.
Looking ahead, the LIB looks set to expand beyond mobile phones, HEVs and EVs, and into new applications such as an environmentally friendly smart grid that will help regulate supply and demand in the industrial and residential power grid. Through our Group’s ability to supply all four main components of LIBs, we are making a significant contribution to the evolution of an important source of power for future generations.
