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Graphene-silicon battery optimisation tests yield higher capacity results for Talga Resources

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By Imelda Cotton - 
Talga Resources ASX TLG graphene silicon battery optimisation anode

Talga Resources has improved the performance of its graphene silicon lithium-ion battery anode product, Talnode-Si.

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Australian advanced materials technology company Talga Resources (ASX:TLG) has reported further performance gains from optimisation tests involving its graphene-silicon, lithium-ion battery anode product Talnode-Si.

Initial tests in October – under the UK Government-funded Safevolt project run by Talga, Johnson Matthey, the University of Cambridge and manufacturing research group TWI – showed the high energy battery could provide approximately 50% higher reversible capacity than commercial graphite-only anodes and a coloumbic attraction efficiency rate of up to 99.8%.

Coloumbic efficiency refers to the ratio (expressed as a percentage) between energy removed from a battery during discharge compared with energy used during charging to restore the original capacity.

Talga has since conducted further optimisation tests using new half-cell cycling and up to 15% silicon loading.

Results included up to 70% higher reversible capacity than commercial graphite and a coloumbic efficiency between 99.5% and 99.9%, with first cycle efficiency of approximately 91%.

Based on the encouraging test results, Talga has opted to progress to full cell testing and optimisation of Talnode-Si.

High-performance replacement

Talnode-Si comprises a mix of silicon and graphene particles engineered by Talga to be suitable for existing lithium-ion battery manufacturing equipment as a high-performance, cost-effective and scalable replacement to standard graphite anode materials.

High-performance battery technology can extend device operating times and driving ranges in electric vehicles.

It can also lead to lower costs, as increased energy density decreases the cost per unit of energy (kilowatt/hour) for the total battery pack.

This increased capacity is a critical metric for end users in China, where lucrative new energy vehicle subsidies are tied to energy density.

Talga said commercial samples are being prepared for some of the world’s largest electronics companies, with delivery due to commence by month end.

High capacity future

Several of the world’s car makers will move to higher energy-to-weight ratios in their next generation battery packs, while other big names in the anode supply chain have committed to the use of silicon technologies in graphite to produce silicon oxide-based graphite.

In September, Volkswagen estimated its cell energy density would increase by 25% from 2018 to 2025 and said it would target 20% silicon anodes from 2020.

Hitachi is piloting a silicon-graphite anode to form higher energy density batteries, while anode manufacturing giant BTR has a silicon-graphite anode in production and is looking to increase silicon loadings.

At midday, shares in Talga Resources were up 5.33% to $0.395.