Critical Resources Limited (ASX:CRR) independent peer reviewed publication confirms DSD dry cathode manufacturing technology

Critical Resources Limited has reported that peer reviewed research validating its dry supersonic deposition (DSD) cathode manufacturing technology has been published in the international journal Electrochimica Acta.

The publication confirms a solvent and binder free cathode manufacturing method and reports lithium iron phosphate cathodes produced using the DSD process in coin cell format against a liquid electrolyte reference system.

The publication states that the DSD process builds cathodes dry in a single step directly onto the current collector with no solvents, no polymer binders and no drying ovens.

The publication reports that conventional cathode manufacturing uses solvent based slurry processing with polymer binders and drying steps to remove solvents such as N-methyl-2-pyrrolidone.

Highlights

• Peer reviewed publication in Electrochimica Acta validating DSD cathode manufacturing process

• Solvent and binder free single step cathode deposition onto current collector

• Approximately 154 mAh/g lithium iron phosphate capacity achieved in coin cell testing

• Approximately 85% capacity retention over 500 cycles at 1C

• Coulombic efficiency above 99.5%

• Heat treatment at ~350°C restores crystallinity in deposited material

• ASE benchmarked at 3.2 mS cm⁻¹ ionic conductivity

The publication reports that as deposited DSD lithium iron phosphate is partially amorphous and has reduced lithium ion diffusion compared to crystalline material.

The publication states that a heat treatment at approximately 350°C restores crystallinity and that this transformation is reversible.

The publication reports that after heat treatment, lithium iron phosphate cathodes deliver approximately 154 mAh/g at 0.1C compared with a theoretical capacity of approximately 170 mAh/g.

The publication reports approximately 85% capacity retention over 500 cycles at 1C and coulombic efficiency above 99.5%.

The publication reports lower rate capability at higher currents in initial unoptimised trials, with further optimisation identified as future work.

The work was conducted at the South Dakota School of Mines and Technology within the US National Science Foundation supported Centre for Solid-State Electric Power Storage, and the program is led by Dr Alevtina Smirnova, Director of the Centre and Technical Advisor to Critical Resources.

Critical Resources states it holds an exclusive option over the intellectual property and provisional patent application relating to the DSD process.

Critical Resources states its strategy is to license its battery materials and manufacturing intellectual property and not manufacture cells itself.

The Company reports that its Amorphous Solid Electrolyte (ASE) has been benchmarked at 3.2 mS cm⁻¹ ionic conductivity and 0.27 eV activation energy.

The Company reports that the ASE is sulphur free and forms part of ongoing work to integrate into a full solid state cell architecture.

Critical Resources Managing Director Tim Wither commented:

“An international peer review is real validation of the work being completed at the South Dakota School of Mines and Technology. Peer review is a high bar, and clearing it helps de risk the process that sits at the core of our evaluation program.”

The Company states that ongoing work includes pouch cell testing, optimisation of the DSD process, independent validation work, and integration of the ASE thin film electrolyte into the deposition system.

The Company states that further work includes trials incorporating ASE and a high temperature electrolyte within the dry deposition process.