Altech Chemicals’ (ASX:ATC) alumina tech successfully coats graphite particles, page-285

The Altech Group, a technology leader for the optimization of batteries in electromobility, achieved a breakthrough in the potential reduction of initial charging losses in the next generation of rechargeable batteries in electromobility. Thanks to the successful application of its aluminum oxide nano-coating technology to silicon particles for anodes, such as those used in lithium-ion batteries, the batteries of the future will also be able to prevent the typical initial charging losses in future batteries.

Altech's solution for initial charge loss

The battery industry has long sought a solution to avoid the initial charge loss that occurs with every battery. When charging for the first time, lithium ions stick to the anode and are no longer available for energy exchange. This leads to an ad hoc energy loss of around 8 percent. Altech's nano-coating with high-purity aluminum (HPA) prevents this negative effect. This additional charging capacity is then available over the entire life cycle of the battery. At the same time, it is possible, for example, to run more power charging cycles without reducing the life of a battery. The successful application of Altech's technology in the coating of graphite particles with fine aluminum oxide was already confirmed at the end of 2020. Now the next technological breakthrough took place:

Game changer silicon coating

The expansion of the application of coating technology to silicon particles is a major breakthrough. Market leaders like Tesla have already announced that they want to increase the amount of silicon in batteries in the future. The aim is to achieve a gradual improvement in energy density and battery life. Compared to graphite, silicon has a theoretical energy capacity ten times higher, which makes it ideal for use in anodes of lithium-ion batteries. What is challenging, however, is the volume expansion of the silicon particles by up to 300 percent when they are energized. In addition, there is an even higher "first cycle lithium loss" compared to the use of graphite. So far, these effects have slowed down further development despite the significant expected improvements in performance. There is consensus in the battery industry that the encapsulation of silicon particles by applying a nano-layer of aluminum oxide can reduce these negative side effects. Altech's existing technology leadership is thus a "game changer" in battery development: Altech paves the way for higher energy density and service life of lithium-ion batteries and lower first-cycle lithium loss. And this also applies to the next generation of more powerful batteries with an increased silicon content. in battery development: Altech paves the way for a higher energy density and service life of lithium-ion batteries and a lower first-cycle lithium loss. And this also applies to the next generation of more powerful batteries with an increased silicon content. in battery development: Altech paves the way for a higher energy density and service life of lithium-ion batteries and a lower first-cycle lithium loss. And that also applies to the next generation of more powerful batteries with an increased silicon content.

Test results show the positive effect

To test its fine particle aluminum oxide coating technology, Altech used silicon samples obtained from its cooperation partner Silico Ferrosolar, a subsidiary of the Ferroglobe Group. Altech was able to adapt the alumina nano-coating to the difficult-to-master unique properties of silicon particles. An even and consistent layer of aluminum oxide was deposited on the outer edge of the silicon particle, encapsulating the particle. This is the decisive prerequisite for achieving the desired positive effect of avoiding lithium binding on the anode. Lithium ions cannot get stuck on such a smooth surface on an atomic scale. This is the desired effect of Altech's unique aluminum oxide coating technology.

The next steps: battery test

The next step in the test process is to incorporate the coated silicon particles into a battery anode and perform battery performance tests. These series of tests will aim to demonstrate and quantify the potential performance gains and life improvements of lithium-ion batteries with Altech's HPA-coated silicon anodes.

For Altech Chemicals Limited's General Manager Operations and Chief Scientist, Dr. Jingyuan Liu, the verification of Altech's coating technology on silicon particles is an important milestone in the ongoing development: "The almost perfect coating results that have been achieved through the application of our technology are very encouraging. Such smooth surfaces at the nano-level have the potential for the use of Significantly increase silicon in lithium-ion battery anodes and thus increase the energy density, overall performance and longevity of batteries. The next step is to further optimize the coating process. " Altech expects the first results of the battery performance tests to be available in the second quarter of 2021.