SATPC0038449 Tab 04 4 SOW.pdf

Robust Safety with Plastic Current Collectors in Cylindrical Li-ion Cells

SOW

23 Apr 2025

1.0 Objective – Improve the robustness of the safety of 21700 cell designs using metallized plastic current collectors (MPCC) and all-ceramic separators (ACS) to isolate internal short circuits caused by nail penetration and internal short circuit devices.

2.0 Scope – Design, build, and test several iterations of Li-ion 21700 cells with MPCC and ACS and improve robustness of safety by eliminating the winding process for the fragile all-ceramic separator, switching to a MPCC that doesn’t use polyester, and verifying safety with a smaller diameter ISC device. Focus first on slot-die coating the ACS on the anode to obviate winding the fragile but thermally stable ACS. After showing nail penetration tolerance, then switch to a MPCC with a 6 µm polymer layer that’s not polyester. After showing nail penetration tolerance, then build a larger quantity to enable a subset to be implanted with a ¼” diameter ISC device. The larger quantity build will include control cells metal foil collectors and with the ACS.

3.0 NASA Inputs – Calorimetry with high-speed radiography of cells in thermal runaway along with tomography of surviving cells pre and post. NASA will fund KULR to provide the ISCDs.

4.0 Contractor Tasks

4.1 Separator Development

• Produce an electrode anode

• Attempt slot-die coated separator on anode

Cylindrical Cells - 216 cans/headers (3-5 cells)

Cell Group Current Collectors

Separator ISC Device

Capacity

1 PET MPCC Slot-die coated ACS No 5.0Ah

2 PET MPCC Standard ACS No 5.0Ah

3 PP-MPCC Depends on Results from

(1) and (2)

No 5.0Ah

4.2 Design Round 2: After demonstrating nail penetration tolerance in Design Round 1.

Cylindrical Cells – 216 cans/headers

Cell Group Current Collectors

Separator ISC Device quantity

A PET MPCC Slot-die ACS No 40

B Non-PET MPCC Slot-die ACS No 40

C PET MPCC Slot-die ACS Yes 10

D Non-PET MPCC Slot-die ACS Yes 10

E Metal foils Slot-die ACS No 10

F Metal foils Slot-die ACS Yes 10

4.3 Test – Perform nail penetration on 3-5 cells from each cylindrical cell group (1 to 3) at 100%

SoC. Perform nail penetration on 3-5 cells from groups A to D at 100% SoC.

5.0 Deliverables

5.1 Data – Cell build plan shall be provided prior to committing to assembly. Cell formation, capacity, and impedance shall be provided prior to shipping and nail penetration testing.

Nail penetration test debriefing. All data shall be provided to eric.c.darcy@nasa.gov within 1 week of each testing cycle completion. Team will hold weekly meetings with NASA to review progress towards a nail penetration tolerant design. Design changes in future groups of cells will be decided each week.

5.2 Cells – Cells shall be delivered to NASA-JSC within 4 months after contract start date with minimum quantities specified herein.

5.2.1 During development, many different groups of cells will be produced with 3-5 cells per group. Up to 10 different cell groups may be produced. Work will continue until 10 groups have been produced or a NPRC design is achieved.

5.2.2 If a NPRC group is achieved, Coulometrics will deliver the quantities specified in

Table 4.2 to NASA.

mailto:eric.c.darcy@nasa.gov