Sparc Technologies Limited’s (ASX: SPN) development partner the Queensland University of Technology (QUT) as delivered a second project milestone report on a project targeting development of sustainably sourced hard carbon anode material for sodium ion batteries (SIBs).
The report describes the results of SIB half-cell battery testing and material characterisation for multiple samples of the chosen bio-waste material against a commercial benchmark. Electrochemical testing confirms consistently high reversible capacities and ongoing improvements in initial coulombic efficiencies (ICE) for the bio-waste derived anodes using the new processing method under development.
These results have been benchmarked against commercial hard carbon materials under the same testing procedure.
Improving the capacity of hard carbon anodes is considered to be important for increasing the overall energy density of sodium-ion batteries, which is a key limitation to widespread use in mobility applications such as electric vehicles currently.
Given the continuation of positive capacity results as first reported in March 2023, Sparc is planning to accelerate its research and development in this area targeting further optimisation of process parameters and testing to demonstrate a broader suite of battery characteristics. Sparc is also in the process of completing a techno-economic analysis and is conducting testing of the hard carbon materials at an external laboratory.
Sparc is extremely pleased with these results from its research with QUT into the development of sustainable hard carbon anode materials for sodium ion batteries. The feedstock and process is demonstrating high capacity anode material which, subject to further testing and results, holds the potential to improve the energy density and carbon footprint of sodium-ion batteries,” Executive Chairman, Stephen Hunt, said.
“Sparc continues to see momentum building behind sodium-ion batteries as an alternative battery chemistry, driven by raw material availability and cost, and we remain well positioned as one of the only ASX listed companies actively targeting this growing field.”
Test results contained in the recent milestone report were based on the preparation of hard carbon anodes using three different samples of the same category of bio-waste feedstock material (sample A, B and C). The feedstock samples, which differed by location, the amount of upstream processing and ageing, were prepared and carbonised consistently using the method and conditions established in the initial process optimisation, as described in the March 2023 milestone report.
Characterisation of the resulting hard carbon materials using TGA, XRD, XPS, Raman, TEM, SEM, and BET has been performed and will provide a basis for comparison in ongoing testwork. Electrochemical performance was tested in half-cell configuration using galvanostatic charge/discharge at commercial mass loadings and low C-rates (0.05).
Two alternative commercial electrolytes were trialled with improvements in ICE noted with Electrolyte #2. Five coin cells were tested for each trial to ensure the reproducibility of the measurements. All testwork was conducted at QUT’s laboratories in Brisbane.
Whilst there was some increased variability in the reversible capacity results for the bio-waste derived hard carbon materials as reflected by higher standard deviations, every trial yielded higher average capacity than the commercial benchmark, ranging from 3% up to a maximum of 63%. This is considered to be a significant result, particularly in the context of the improvement in ICE using Electrolyte #2.
Also contained in QUT’s milestone report were testing results incorporating surface and process modification techniques, although further work is required to draw meaningful conclusions. Initial proof of concept testing using the bio-waste derived anodes in a full cell format was also reported.
Given the positive results, Sparc is planning to extend its research and development related to this project via the following activities:
- Electrochemical testing of the bio-waste derived hard carbon materials at an external laboratory (underway);
- Developing a cost model / techno-economic analysis to ascertain the potential competitive advantages of the process (underway);
- Continue to optimise performance of half cells including trialling of methods to further improve ICE;
- Developing and testing full cells using commercially available cathode and electrolyte materials;
- Investigations into process scaling;
- Commencing engagement with industry players and potential customers.
Funding of these activities will be through Sparc’s existing cash resources in addition to potential grant funding for which an application has been submitted.
The project milestone report on which the announcement is based is a progress report. The information contained in the announcement is subject to further testing and validation and is subject to change. Investors are cautioned that, whilst underway, no independent validation of QUT’s results has occurred at this stage. This project is still at an early stage of development with a deemed technology readiness level (TRL) of 31.