Silicon anode spinout targets batteries with 50 per cent more energy
The company, LeydenJar Technologies, is targeting electric vehicles (EVs), smartphones, laptops and other electronic devices, as well as grid storage.
After a decade of research and a year of commercial development, the company is in discussions with large international battery manufacturers and wants to open a demonstration plant in 2018. Companies such as Nexeon and SiNode have also been developing silicon anode technology.
The new technology replaces the traditional graphite anode with a pure silicon anode, increasing the storage capacity of the anode in a lithium-ion battery by a factor of ten and the storage capacity of the whole battery up to 50 per cent. However, the silicon expands when the battery is charged and becomes three times larger, which can make the silicon layers brittle and cause the battery material to fall apart. ECN applies the silicon in columns onto copper foil using a plasma-etched chemical vapour deposition (PECVD), creating enough space for expansion and allowing the battery to remain stable. The layer eventually needs to be 10 microns thick for commercial application. 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 said.
“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,” said Sjoerd Wittkampf, Technology Transfer Manager at ECN. “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.”
The PECVD process can precisely manage the porosity of the structure, leading to an anode material that both can achieve a high capacity and remain stable over many cycles. The company has achieved an areal capacity of 2.6 mAh per cm2, and are targeting an area capacity of 3 mAh and higher.
The silicon anode needs to fit with the electrolyte and cathode material in the battery cell, so the company is currently testing various combination of electrolyte additives to manage the interface between our anode and the electrolyte. It plans to test the optimized anode and electrolyte with NMC cathode material in pouch cells in the first quarter of 2017 with the ZSW battery technology institute in Germany.
”Given the widespread use of Li-ion batteries, the company focuses its efforts on three market segments”, says co-founder Christian Rood of LeydenJar Technologies. The goal is to supply the technology to large battery manufacturers. “In our future demonstration plant, we want to produce silicon anodes for our first clients and demonstrate that this technology is competitive when mass-produced. In other words, we want to demonstrate that a better battery can be produced for the same amount of money,” said Rood.