Sparc Technologies Limited (ASX: SPN) has identified a new hard carbon processing technology that is significantly faster and less energy intensive than conventional pyrolysis in its project with Queensland University of Technology (QUT) targeting development of sustainably sourced hard carbon anode material for sodium ion batteries (SIBs).
A high performing, low cost, sustainably sourced anode material for SIBs will meet a need for what is a growing alternative battery technology. Current hard carbon materials are typically sourced from carbonaceous precursors such as pitch (a by-product of the oil & gas industry) which undergo lengthy heating at high temperatures. This is a very energy consuming process, which combined with using a fossil fuel derived feedstock, has a significant environmental footprint.
Furthermore, with China being the world’s dominant supplier of hard carbon materials, the process under development with QUT aims to provide an alternative western supply of anode materials thereby reducing sovereign risk for SIB cell manufacturers.
Sparc is very encouraged by the positive results from its research program with QUT into the development of sustainable hard carbon anode materials for sodium ion batteries. The combination of green bio-waste feedstock and faster, less energy intensive processing with a very high capacity anode material offers attractive potential for further research and development,” Executive Chairman, Stephen Hunt, said.
“Equally as exciting is the continued progress of sodium ion batteries towards commercialisation as evidenced by recent activities of major global battery producers including CATL, BYD and Reliance Industries. Sparc is well positioned as one of the only ASX listed companies actively targeting sodium ion batteries.”
In line with the project schedule, QUT has delivered the first project milestone report which describes the results of SIB half-cell battery testing and material characterisation for a sustainably sourced anode material under a range of process conditions.
Whilst further optimisation, testing and process development work is required, reversible capacities for a batch of materials under the same testing conditions exceeded 535mAh/g and averaged 477mAh/g across five separate trials. This was well beyond (~45% higher) the benchmark of 330mAh/g set at the beginning of the research programme based on what is believed to represent commercial hard carbon anode materials.
Significant progress has been made since commencing the research project with QUT in September 2022. Preliminary optimisation of the process conditions under which the hard carbon is produced has been performed and the initial results demonstrate substantial improvement in reversible capacities of the anode materials in a SIB versus traditional pyrolysis methods.
Material characterisation of the hard carbon samples using various characterisation techniques (XRD, XPS, Raman, TEM, SEM, and BET) has been performed and will provide a basis for comparison in future test work, such as trialling alternative feedstock sources and process parameters.
Sodium-ion battery performance of samples (in half-cell configuration) has been tested using electrochemical methods such as galvanostatic charge/discharge – capacity and cycling stability. Several coin cells (5 cells for each hard carbon sample) were made for each electrode to ensure the reproducibility of the measurements and commercial mass loadings and low C-rates (0.05) were used.
Future work will focus on testing cycling stabilities up to 500 cycles, trialling methods to improve initial coulombic efficiencies and fabrication and testing of full cells. Sparc has ~6 months to run on the research programme with QUT and continues to engage with an experienced battery consultant on the project.
Sparc is planning to further explore the magnitude of energy and cost savings achievable through using the proposed processing route over existing hard carbon materials via life cycle analysis and economic modelling over the coming months.
SIBs are a very prospective alternative battery chemistry to lithium ion, particularly suited to energy storage markets. Well known and documented advantages of SIBs versus lithium ion batteries include:
- Lower cost and greater availability of raw materials.
- Safety and ease of transport.
- Greater operating temperature range.
- Similar manufacturing techniques to lithium ion batteries
These benefits, in particular around supply and cost of raw materials, have seen growing activity by energy developers, original equipment manufacturers (OEMs) and venture capital investors in SIBs. Commercialisation of SIBs for energy storage and mobility applications is targeted in 2023 by CATL, BYD, Reliance / Faradion and HiNa Battery. The requirement for the continued promotion and development of SIB technology has been noted by CATL.
