Development of Printing Technology to Enhance the Safety of Lithium-Ion Batteries

Abstract

There is an increasing demand in the market for lithium-ion secondary batteries that are large in size and have a high energy density. However, this comes with the challenge of safety compliance. We have developed a technology to print a heat-resistant ceramic layer on electrode using Ricoh printing technology. Alumina (Al₂O₃), which has a heat resistance of 1000°C or higher, was converted into an inkjet ink and printed directly on the electrode to improve the safety of lithium-ion secondary batteries during abnormal heat generation. In addition to this, we have resolved issues found in other printing methods pertaining to print quality and decreased output performance by changing the ink composition and materials used. Since ink jet printing is a non-contact printing method, we were able to execute thin film printing without damaging the base electrode. Moreover, to establish higher-order safety technology for inkjet printing of battery materials, we are currently developing a heat-resistant separator to replace the current polyolefin separator and the separator layer printing technology with a solid electrolyte material that does not use combustion.