High performance LiPON electrolyte via Atmospheric-Pressure Large-Area spatial Atomic Layer Deposition
High performance solid-state electrolytes and interfacial layers are crucial to achieve next-generation lithium-ion batteries with a longer lifespan, faster charging and intrinsic safety. Today, Holst Centre, powered by TNO, announces that for the first time spatial-ALD deposition of lithium phosphorus oxynitride (LiPON) as a solid electrolyte has been achieved. The sALD LiPON process uses commercially available chemicals, making it cost-effective to integrate it into commercial Li-ion battery production.
Until now, a very limited number of deposition methods could be used to fabricate high-quality, solid-state electrolytes, especially on porous battery electrodes. Among these techniques, atomic layer deposition (ALD), a thin-film deposition process via successive reactions of gaseous chemicals on solid substrates, shows the best conformity on complex structures. However, conventional vacuum-based batch ALD process restrictions make ALD a very difficult choice for battery manufacturing at reasonable cost and throughput. Holst Centre, powered by TNO, provides prime solutions for the integration of flexible electronics including high performance batteries and offers a high-throughput ALD solution. One of Holst Centre's key technologies is atmospheric pressure spatial ALD (sALD), which has now been applied to achieve a significantly faster LiPON process.
Dr. Mahmoud Ameen, project leader and scientist: "For the first time ever, we have achieved sALD LiPON with an ionic conductivity higher than 1 × 10-6 S/cm at room temperature, at the same time having a very low electronic conductivity of around 1 × 10-13 S /cm. The sALD-grown LiPON is pinhole-free even at 10s of nanometer film thickness, and can be produced with a throughput that is at least 10 times higher than any reported ALD-based LiPON."
Compatible and cost-effective
"The LiPON layer can be applied not only as a solid electrolyte, but also as an interfacial passivation layer (e.g. artificial SEI) on state-of-the-art battery electrode foils. The sALD LiPON process is compatible with atmospheric pressure roll-to-roll manufacturing, and uses commercially available chemicals, making it cost-effective to integrate into commercial Li-ion battery production" says Dr. Sandeep Unnikrishnan, manager of Holst Centre's high-performance batteries program.
Spatial ALD (sALD)
Spatial ALD is a novel variant of the atomic layer deposition (ALD) technology. It offers the same precise control and uniformity of film composition and thickness as traditional ALD, but at much higher deposition rates – around 1 nm/s. Moreover, sALD is an atmospheric pressure process and does not require costly vacuum equipment. Holst Centre, powered by TNO, has successfully upscaled sALD to large areas in sheet-to-sheet and roll-to-roll equipment, and can achieve highly uniform layers even for structures with an extreme aspect ratio. The technology is ready to be integrated into commercial production of, e.g., thin-film solid-state batteries, optical stacks, thin-film photovoltaics and semiconductor and dielectric layer stacks for a host of large-area applications.
• For more information on sALD-based battery interfacial engineering, please check this video
• Holst Centre, powered by TNO, hosted this webinar on applications of sALD for Next-Gen battery development on 9 June 2020