This Small Business Innovation Research (SBIR) Phase I project will further develop an all solid state lithium battery comprised of a sulfur-based solid-state electrolyte, a high capacity nanostructured cathode and a metal lithium alloy anode. The proposed program is based on research performed at the University of Colorado at Boulder where preliminary stable cycling of this lithium-ion system has been demonstrated. The proposed technology addresses the stability issues experienced by previous efforts in utilizing a lithium metal anode in combination with conventional liquid electrolytes. Further, the proposed technology also addresses the conductivity and rate capability issues experienced by previous effort in utilizing a lithium metal anode in combination with a solid-state electrolyte. Thus if successful, the proposed technology will result in ultra high energy batteries with specific energy and power at or above 600 Wh/kg and 1 kW/kg, respectively. Further, the proposed technology also eliminates all safety concerns associated with conventional lithium-ion batteries due to the inherent safety and stability characteristics of solid-state electrolytes.
The broader impact/commercial potential of this project is considerable as virtually all battery powered products in the commercial and military marketplace share the need for greater energy per unit mass and/or volume. If successful, it is anticipated that the proposed technology will result in lithium-metal batteries having specific energy and power greater than or equal to 600 Wh/kg and 1 kW/kg, respectively (note: specific energy and power for current state-of-the-art lithium-ion batteries: 200 Wh/kg and 1 kW/kg, respectively). Further, the use of a solid-state electrolyte-based lithium-ion system gives rise to vastly improved safety, reduced system complexity and cost (by eliminating or minimizing safety electronics and some packaging), improved cycling stability and excellent shelf life as compared to conventional technologies. Thus if proven technically and commercially viable, the proposed technology could have considerable commercial impact within the multi-billion dollar annual rechargeable battery market. Potential product applications include electric vehicles, consumer electronics (cell phones, computers, etc.), aircraft and aviation and military power among several others.
Solid Power’s Phase I SBIR project focused on demonstrating the feasibility of an ultra high energy, safe and low cost all solid-state rechargeable battery. Solid Power’s technology combines an ultra high capacity composite cathode, a solid-state electrolyte and a lithium-metal anode. Phase I goals included optimizing the ultra high capacity cathode leading to high cell energy and optimizing the solid-state electrolyte for density and dendrite suppression vs. the lithium-metal anode. Both Phase I goals were achieved. First, a novel cathode synthesis process was established leading to intimate interfacial contact in-situ between active material and solid electrolyte particles in the composite cathode. This led to a nearly 50-percent increase in capacity or, one of the highest reported cathode capacities in solid or liquid batteries. Further, cathode thicknesses up to 200 microns were demonstrated. Both achievements are essential in enabling a high energy cell. Second, the density of the solid-state electrolyte was increased using a hot isostatic press method leading to a nearly 50-percent increase in ionic conductivity. Finally, cell cycling stability was demonstrated in full-cell form. The commercial impact potential for the all solid-state rechargeable battery is considerable if proven technically and commercially viable. Virtually every sector of the multi $BN rechargeable battery market has a substantial need for increased battery charge time at reduced or comparable weight and/or volume. Specific target markets include automotive, aerospace, military, medical and consumer electronics among others.
