Ready-to-Cast Solid Electrolyte Slurry for Li-Ion Batteries

February 11, 2015 by Jeff Shepard

NEI Corporationhas announced the availability of a ready-to-cast solid electrolyte material. Over the past year, NEI has supplied multi-kilogram quantities of their newly developed solid electrolyte powder, NANOMYTE® SSE-10 (Li10SnP2S12 or LSPS). NANOMYTE® SSE-10, which has been used by a number of scientists and engineers for developing and prototyping "all solid" lithium-ion batteries, is now available in the form of a slurry (dispersion), NANOMYTE® SSE-10D, which can be cast into flexible tapes. NANOMYTE® SSE-10D is composed of surface-modified LSPS particles dispersed in organic solvent, which can be removed after the tape or film is formed.

Lithium Tin Phosphorous Sulfide (LSPS) belongs to a family of “superionic” solids, which have demonstrated high conductivity for lithium ions at room temperature. Commercial lithium-ion batteries usually contain an electrolyte that is dissolved in flammable solvents. The use of a solid electrolyte eliminates the flammability issue associated with currently used liquid electrolytes.

Sulfide compounds with high Li-ion conductivity are not commonly available, and as such, the development of solid state electrolyte–based lithium-ion batteries has been plagued by the lack of widespread availability of these difficult-to-produce materials. Sulfur-based superionic solids with high Li-ion conductivity (10-3 S/cm) at room temperature (and more than an order of magnitude higher at 60 degrees C) were not commercially available until over a year ago when NEI first introduced LSPS in powder form. Since then, SSE-10 powder has been tested by industrial corporations (automotive, electronics, oil and gas) as well as academic and research institutes.

By offering the material in slurry form, SSE-10D can be readily cast into films and tapes and provides more options for cell designers to combine with suitable cathode and anode active materials. Additionally, the dispersion allows limited atmospheric stability to the solid electrolyte particles, which otherwise need to be handled in a controlled environment. NANOMYTE® SSE-10D is available in small as well as bulk quantities, and it can be supplied in customized formulations, with the addition of an active material (such as LCO, LFP, NCA, LMNO, graphite, and LTO). The generic NEI process is amenable to synthesizing variants of LSPS (e.g., compositional changes), as well as other oxide-based solid electrolyte materials

“The introduction of NANOMYTE® SSE-10 last year, and now SSE-10D, will provide new capabilities to lithium battery developers and manufacturers to enable practical solid state batteries,” said Dr. Ganesh Skandan, CEO of NEI Corporation. He added, “By making solid state electrolyte materials available in a ready-to-cast form, our intent is to make it easier for Li-ion battery researchers to develop the next generation of all-solid-state lithium ion batteries.”