ASX-listed high purity alumina or “HPA” player, Altech Chemicals says it has kicked off battery performance testing of graphite particles that have been coated with HPA using its alumina-coating technology. It comes after what the Perth-based company described as the successful demonstration of the technology to coat graphite particles, typical of those used in anode applications within lithium-ion batteries, with a nano layer of HPA.
According to Altech, the demonstrations that were carried out at Western Australian universities late last year showed its technology successfully depositing a uniform and consistent layer of alumina of approximately 2 nanometres thick onto anode-grade graphite particles.
Uniformity and consistency of an alumina layer or coating on anode-grade graphite are thought to be pivotal to improving lithium-ion battery performance and life, the company says.
Following completion of the demonstrations, Altech produced a quantity of coated graphite deemed sufficient to progress to first-stage battery test work, which has now commenced.
Altech Chemicals Managing Director, Iggy Tan said recently: “We are very encouraged by the near perfect coating results from our technology which has the potential to significantly impact lithium-ion battery performance and address the problem of ‘first cycle capacity loss’. The next stage of work is battery performance testing using our alumina coated graphite, which will aim to demonstrate a step change in battery energy density capacity, performance and battery life.”
For Altech’s tests or trials, a batch of electrodes has been produced using non-coated standard anode-grade graphite particles for the control, and a separate batch has been produced using the anode-grade graphite that is coated with HPA via its alumina-coating process.
The company says the initial tests, to battery industry standards, are an important first step to demonstrating the gains to be made in lithium-ion battery life using HPA-coated graphite particles.
HPA is commonly applied as a coating on the separator sheets used within lithium-ion batteries, with the alumina-coated separators improving battery performance, durability and safety.
Altech suggests there is an emerging use for alumina within the anode component of a lithium-ion battery due to the positive effect alumina-coated graphite particles have on battery life and performance.
Lithium-ion battery anodes are typically composed of graphite. In a lithium-ion battery, lithium-ion losses initially present as inactive layers that form during the first battery charge cycle. The losses then compound with each subsequent battery usage cycle.
Typically, about 8 per cent of lithium ions are lost during the first battery charge cycle, known as the “first cycle capacity loss” or “first-cycle irreversibility”, a long recognised but as yet poorly resolved limitation that has plagued rechargeable lithium-ion batteries.
The graphite particles currently used in lithium-ion battery anodes are uncoated, however, Altech says manufacturers are now seeking to coat anode graphite particles with a very thin layer of alumina.
According to the company, previous test results have indicated alumina-coated graphite particles have the potential to reduce first cycle capacity loss. In turn, such an innovation can significantly increase battery energy retention, extend battery life and improve overall battery performance.
Altech says the just-launched battery performance trials will look to quantify the potential lithium-ion battery performance and lithium-ion battery life-cycle improvements using its HPA-coated graphite anodes.
In the event its HPA graphite particle-coating technology graduates to commercial status, Altech hopes to produce an anode-grade product range at its proposed HPA plant in Johor, Malaysia.
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By Matt Birney
