High-capacity Film-type Li-ion Battery Developed Using Coating Process

Sekisui Chemical Co., Ltd. has developed a high-capacity film-type lithium-ion battery using a coating process that has simultaneously tripled its capacity (compared to other Sekisui Chemical products), increase its safety (as a result of standard safety testing, e.g. no problems with nail penetration tests or crush tests) and speeded up production by ten times (compared to other Sekisui Chemical products).

“Normally solidifying liquid electrolytes is said to lead to a drastic reduction in lithium-ion conductivity,” observed Satoshi Uenoyama, Director of Research and Development with Sekisui. “At Sekisui Chemical, we have used our original materials technology to utilize novel high-performance gel-type electrolytes with high lithium-ion conductivity (approx. ten times compared to other Sekisui Chemical products) to realize high productivity with a coating process instead of the standard vacuum infusion process.

“By further adding our newly developed, original materials technology of high-capacity silicon negative-electrode material in this process, we can provide high-capacity film-type lithium-ion batteries with overwhelmingly high productivity while being flexible, slim, long and covering a large area. They make unprecedented savings in terms of space (a third the size of previous products) and can be installed in any shape or form, giving rise to a large number of applications in automobiles, houses, appliances and so on,” Uenoyama concluded.

Part of the results of this research and development (the process technology) was achieved with support from the Advanced Technology Research Project for the Application and Commercial Use of Lithium-Ion Batteries being run by the New Energy and Industrial Technology Development Organization (NEDO). The achievements of this research will be formally announced at Eco-Products 2013 to be held at Tokyo Big Sight on December 12-14 this year. In the future Sekisui will focus on developing mass production with these film-type lithium-ion batteries, aiming at quickly realizing products for a variety of uses, including electric vehicles.

Sekisui Chemical has also developed high-capacity silicon negative-electrode materials to make optimum use of this performance, realizing a high-capacity battery cell (900Wh/L). The development of high-capacity film-type lithium-ion batteries giving practical performance while being flexible, slim, long and covering a large area is expected to greatly improve freedom in designing the shape of the final products, leading to anticipation for their use in automobiles, houses, electrical appliances and so on while gaining unprecedented lightness, space-saving (a third the size of previous products) and enhancing design through being able to be installed in any shape of form.