Silatronix, a developer of unique organosilicon (OS) electrolytes for use in lithium-ion batteries (LIBs) (earlier post), has raised US$8 million in new equity capital, and secured partnerships for distribution and joint technological development. These funds and partnerships will allow Silatronix to capitalize on the commercial value of its portfolio of OS materials in the high-growth LIB market.
The capital comes from the company’s existing investors and two strategic partners in Japan with strong business interests in the LIB market: Hitachi Chemical Co., Ltd. and Inabata & Co Ltd. Inabata will serve as Silatronix’s exclusive distributor to key LIB customers across Asia. Silatronix and Hitachi Chemical will jointly evaluate the potential performance benefits of several OS additive materials with Hitachi Chemical’s LIB products, especially anode materials. Silatronix, a spin-out from the University of Wisconsin-Madison, has introduced its first commercial product, a third-generation organosilicon material (OS3)—an advanced functional solvent that provides multiple benefits to LIB performance at additive levels.
|Silatronix’ OS3 (green line) demonstrates significantly superior thermal stability compared to conventional carbonate electrolytes. Usrey et al. Click to enlarge.|
In LiB electrolytes, OS3 inhibits breakdown of LiPF6, is thermally and electrochemically stable, and has minimal side effects on battery performance. Silatronix says that it is making significant progress with multiple customers, many based in Asia, that cover a range of LiB applications, including consumer electronics, industrial products, automotive, and military.
As part of its operational scale up to commercialize OS3, Silatronix is currently formalizing relationships with strategic suppliers, expanding facilities in its Madison, Wisconsin operation, working with Inabata to increase market presence, and hiring key operating personnel.
BDA Partners is acting as exclusive financial advisor to Silatronix.
OS electrolytes. Current Li-ion electrolytes are unstable above 60 °C and at charge voltages above 4.3 volts. They also exhibit flashpoints around 35 °C, and are the major source of the energy released during an extreme Li-ion cell failure. These characteristics are impeding the development of advanced Li-ion batteries for all applications, Silatronix says.
OS electrolytes are compatible with all lithium (Li)-based electrochemical systems, including non-rechargeable batteries, Li-ion, Li-air, and Li-battery/capacitors. The process of designing OS electrolytes into a Li battery involves limited changes in the cell design, and these electrolytes can be incorporated into production operations with existing manufacturing processes and equipment, according to the company.
Silatronix’ basic approach merges a silane with a lithium-coordinating functionality, such as polyethylene oxide units. This combination results in solvents comprising low molecular-weight molecules and having unique properties including high thermal stability, high flash point, low vapor pressure and relatively low viscosities.
Because of the broad set of potential applications, there are many possibilities to fine-tune the properties that need to be enhanced in a molecule. Silatronix is on its third-generation product.
The first generation OS compounds were characterized by a Si-O bond, which is responsible for the excellent thermal stability of silicone polymers and enabled the production of OS electrolytes with high thermal stability.
Silatronix identified Gen-2 structural variants via mechanistic studies. The Gen-2 compounds provided even greater stability under more aggressive conditions. Gen-2 OS solvents have thermal, chemical, and electrochemical properties that surpass those of the original compounds by introducing a less polar (i.e., more stable) Si-C bond, which is less susceptible to attack by fluorinated species, (e.g., HF and PF5).
The Gen-3 solvents are based on an entirely new set of OS molecules, whose thermal, chemical, and electrochemical properties greatly surpass those of the earlier suite of OS compounds. The leading candidate from the Gen-3 OS structural family is OS3 which showcases greatly enhanced stability and performance attributes when compared to the stable Gen-2 molecules.
OS3 offers higher conductivity and lower viscosity while concomitantly providing superior thermal stability with LiPF6 and enhanced voltage stability at both the cathodic and anodic extremes when compared to both carbonate and previous generation Silatronix OS solvents.
Monica Lee Usrey, Adrian Pena Hueso, Michael Pollina, Peng Du, Liu Zhou, Tobias Johnson, Robert J Hamers, and Robert West (2015) “Organosilicon-Based Electrolytes with Superior Thermal and Electrochemical Stability to Enable High Energy Lithium Ion Batteries” Abstract 332, Progress in Electrolytes I