Critical Resources hails sulphur-free battery breakthrough
Brought to you by Bulls and Bears
Doug Bright
Critical Resources has stepped up its battery technology program after reporting that its sulfur-free electrolyte provides room temperature performance comparable to leading sulfur-grade materials.
The company says that in tests conducted at the South Dakota School of Mines and Technology in the US, its first-pass amorphous solid-state electrolyte returned an ion conductivity of 3.2 milliSiemens per centimeter and an activation energy of 0.27 electron volts.
These numbers are two of the key measurements used to evaluate electrolyte performance; The result shows that lithium ions can move quickly through the material without the temperature sensitivity that has traditionally hindered many competing chemistries.
More importantly, the company says the values measured in South Dakota are compared to published, peer-reviewed scientific literature, providing an externally referenced basis for comparing current and future performance.
‘This is early stage laboratory validation, but the technical values are quite encouraging.’
Tim Wither, general manager of Critical Resources
The biggest reward for Critical is manufacturability. Sulfur electrolytes are widely considered to be the best performers, but they can release toxic gas when in contact with moisture and generally require treatment in an inert atmosphere; This has long been seen as one of the main obstacles to commercial scale-up.
Achieving equal transport performance without sulfur could point to a safer and potentially lower-cost production path, the company says.
The result also puts greater emphasis on Critical Resources’ broader range of battery power. In late April, the company said it received an evaluation license for its thermal management technology from Singapore’s Nanyang Technological University, and then converted it into a full commercial license worldwide last week.
This technology aims to cool lithium-ion batteries and high-density electronics in hotter working environments by spraying a non-conductive liquid directly onto hot components, providing the company with a parallel work flow on battery thermal management.
Tim Wither, managing director of Critical Resources, said: “Comparing our first pass ASE results with published peer-reviewed literature reveals a performance position that is the result of years of collaborative research by Dr Smirnova and the SDM team. Being competitive on ionic conductivity and matching the sulfur class activation energy from the starting composition is a strong starting point.”
Critical says the electrolyte run also complements the dry supersonic deposition manufacturing program, with both streams designed to reduce material and manufacturing risk while the company works on more representative solid-state cells.
The company says its new amorphous solid-state electrolyte provides ionic conductivity competitive with non-halide amorphous electrolytes and an activation energy comparable to sulfide electrolytes, but without the challenges associated with sulfide-based chemistry.
Both test results were from a non-optimized battery electrolyte composition and further potential improvements are likely to be made with ongoing studies. Accordingly, the company’s next steps will include improving the electrolyte composition and conducting interfacial tests to analyze how effectively lithium ions move across solid-to-solid boundaries.
The compression studies will test how well battery materials remain bonded during operation, an important step before the company moves on to more advanced battery cells. The work will also focus on making sure the electrolyte works properly with the battery’s cathode before full-cell testing begins.
The company recognizes that it is in the early days of development and does not yet claim to be commercially ready. However, its latest benchmark victory certainly seems to have given Critical a strong talking point in a crowded battery race.
If lab studies continue to yield results, the market may start paying more attention to what’s quietly becoming a broader battery play.
Is your ASX-listed company doing something interesting? Contact: mattbirney@bullsnbears.com.au
