Altech Chemicals (ASX: ATC) has achieved a breakthrough in the development of silicon alumina coating at an opportune time as US electric vehicle manufacturer Tesla has called for more silicon in its lithium-ion batteries.
The emerging high purity alumina (HPA) producer today announced the successful application of its alumina nano layer coating technology to the coating of silicon particles, typical of those used in lithium-ion battery anodes.
The news follows the company’s December revelation that its technology had also successfully been used to coat graphite particles.
Altech general manager of operations and chief scientist Dr Jingyuan Liu said the company has been encouraged by the “excellent” coating results.
“[Our technology] has the potential to significantly increase the use of silicon in lithium-ion battery anode and consequently the potential to increase the battery energy density, overall performance and longevity,” he said.
“The next step is to further optimise the coating process.”
Silicon replacing graphite in battery anodes
Tesla recently announced its aim to increase the amount of silicon in its batteries to improve energy density and battery life, as it has 10 times the theoretical energy capacity compared to graphite.
However, Altech said limitations for silicon use in battery anodes include particle volume expansion of up to 300% when energised and a large “first cycle lithium loss”.
“Industry believes that the encapsulation of silicon particles via the application of nano layer of alumina can resolve these issues and be a game changer, which would pave the way for increased lithium-ion battery energy density, lifespan and reduced first cycle lithium loss,” the company stated.
An industry milestone
According to Altech, the nano coating of alumina onto battery-grade anode materials has been difficult for industry to achieve and as such, the company’s coating technology needed to be adjusted to achieve the required outcome.
“Altech was able to deposit a uniform and consistent layer of alumina on the outer edge of the silicon particle, encapsulating the particle,” it announced.
Altech used silicon samples provided by its new partner Silico Ferrosolar to test its HPA coating technology. This 12-month collaboration was announced last November and involves Altech supplying its coating technology and sole funding the test work.