ALTECH BATTERIES LIMITED The patent describes Altech's technology for alumina-containing coating. The alumina coating layer, when applied to anode materials such as graphite and silicon would serve as an artificial solid electrolyte interface (SEI), which is expected to reduce lithium ion losses during each charge and discharge cycle of a rechargeable lithium-ion battery (e.g. as used in electric vehicles), and also retard degradation of battery capacity.
On
A successful first round of battery testing of Altech's alumina coated graphite has also been completed. For this test, a batch of battery electrodes were produced using non-coated standard anode grade graphite particles (the control) and a separate batch was produced that contained anode grade graphite particles coated with HPA using the Company's technology. One hundred cycles of cell charge and discharge were completed and results for the coated graphite anodes compared to the non-coated anodes were positive and encouraging.
Background
HPA is commonly applied as a coating on the separator sheets used within a lithium-ion battery, as alumina coated separators improve battery performance, durability and overall safety. However, there is an evolving use for alumina within the anode component of the lithium-ion battery because of the positive impacts that 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 very first battery charge cycle, the losses then compound with each subsequent battery usage cycle. Typically, around 8-10% of lithium ions are lost during the very first battery charge cycle. This 'first cycle capacity loss' or 'first-cycle irreversibility' is a long recognised but as yet poorly resolved limitation that has plagued rechargeable lithium-ion batteries.
First cycle capacity loss in a rechargeable lithium-ion battery is because of the deposition of lithium ions onto the anode graphite particles within the battery during the initial battery charge cycle. This forms a layer of material on the anode, termed a 'solid electrolyte interphase' (SEI). Currently the graphite particles used in lithium-ion battery anodes are uncoated, however manufactures are now seeking to coat anode graphite particles with very thin layers of alumina. Tests have demonstrated that alumina coated graphite particles have the potential to reduce first cycle capacity loss. In turn, this innovation can measurably increase battery energy retention, extend battery life and improve overall battery performance.
About
HPA is a high-value, high margin and highly demanded product as it is the critical ingredient required for the production of synthetic sapphire. Synthetic sapphire is used in the manufacture of substrates for LED lights, semiconductor wafers used in the electronics industry, and scratch-resistant sapphire glass used for wristwatch faces, optical windows and smartphone components. Increasingly HPA is used by lithium-ion battery manufacturers as the coating on the battery's separator, which improves performance, longevity and safety of the battery. With global HPA demand approximately 19,000t (2018), it is estimated that this demand will grow at a compound annual growth rate (CAGR) of 30% (2018-2028); by 2028 HPA market demand will be approximately 272,000t, driven by the increasing adoption of LEDs worldwide as well as the demand for HPA by lithium-ion battery manufacturers to serve the surging electric vehicle market.
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Email: info@altechchemicals.com
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