Author Dr. Simon Madgwick of Nuvvon Inc.
Nuvvon Solid State Passes Nail Test with Graphite-NMC811 and Lithium-NMC9
Nuvvon has been building solid state cells for years and has long since exposed the things SSB players don’t tell you. There are some 60 so called Solid-State offerings out there but none with a completely dry cell that operates without compression.
- Cathode: NMC811
- Anode: Graphite
- Electrolyte: Polymer NUVVON-301
- Nominal Capacity = 1 Ah
- Nominal Voltage = 3.75V
- Gravimetric Energy Density
- Cell = 260 Wh/kg
- Stack = 297 Wh/kg
- Volumetric Energy Density
- Cell Charged = 622 Wh/L
- Cell Discharged = 642 Wh/L
- Stack (Charged) = 730 Wh/L
- Cathode: NMC9
- Anode: Li-Metal
- Electrolyte: Polymer NUVVON-201
- Nominal Capacity = 1 Ah
- Nominal Voltage = 3.9V
- Gravimetric Energy Density
- Cell = 368 Wh/kg
- Stack = 418 Wh/kg
- Volumetric Energy Density
- Cell Charged = 947 Wh/L
- Cell Discharged = 1,076 Wh/L
- Stack (Charged) = 1,156 Wh/L
Does it matter, being completely dry? Is it ok to use a solid separator electrolyte but still liquid catholyte? You could ask those who make semi-solid / quasi-solid / undisclosed-solid / supposedly-solid / not-actually-solid-but-crazily-called-all-solid cells; or you could see if they provide safety test data such as nail-pen and ARC.
The Nuvvon nail test comparison is straightforward. Identical traditional cells of commercial grade (1Ah, Gr-NMC811). One used Nuvvon solid polymer electrolyte throughout (SPE) and the other used conventional liquid electrolyte. The nail tests were conducted independently at University Texas Austin (AKA John Goodenough’s old lab).
Guess what? The liquid electrolyte cell went BANG instantly when shorted by the nail but the Nuvvon SPE cell did not. This was followed by an even tougher challenge: Lithium metal anode with NMC9 cathode. Still no reaction when the nail punched through the cell.
Watch this space for 5Ah cells.
So what is Nuvvon SPE? It is a pure polymer system – no sulfide or oxide nanoparticles – not a composite. It has great room temperature ionic conductivity (>1mS/cm at 25°C). It enables thin format separators (≤20µm) and is used as catholyte/anolyte and separator. It utilizes low cost, easy to procure raw materials and the cells are made on the existing Li-ion process.