The technology replaces the conventional graphite anode (of a lithium-ion cell) with a pure silicon anode, increasing the storage capacity of this component of the lithium-ion battery by a factor of ten and the storage capacity of the whole battery up to 50%. However, the problem with silicon is that it expands when the battery is charged and that component increases in size three-fold, which can make silicon layers brittle and cause the battery material to fall apart.
ECN applies the silicon in columns onto copper foil using a plasma-based nanotechnology, thus creating enough space for expansion and allowing the battery to remain stable. The layer ultimately needs to be 10 microns thick for commercial application, which is ten times thinner than a sheet of paper.
ECN researcher Wim Soppe already discovered the material twelve years ago, when he was developing thin-film solar cells. “The material was unsuitable for solar cells, but we found that the technology is extremely promising for lithium-ion batteries. An nice example of how a failure can turn into a success,” he says.
Sjoerd Wittkampf, Technology Transfer Manager at ECN says tremendous effort is put into research worldwide to improve lithium-ion batteries, and acknowledges that, “A breakthrough is claimed every few weeks. These discoveries usually concern materials that can only be produced in a laboratory environment on a very small scale."
"What makes the invention of ECN so promising is that the technology for mass production of this material is already within reach due to its similarity to an existing production process for solar cells. We believe that this gives us a unique advantage. Through the founding of LeydenJar Technologies, we will transfer this technology to the market and create a fit between the battery industry and venture capital investors.”