Australian innovator Altech Chemicals Ltd. released a report yesterday detailing the firm’s expectations regarding the use of high-purity alumina (HPA) in next-generation lithium-ion batteries, which it says is likely only to increase in the coming years.
The report begins by explaining the mechanics of a lithium-ion battery, which essentially consists of an anode, a cathode, and a liquid electrolyte that is divided by a polymer divider. Lithium ions utilize the liquid electrolyte as a pathway between the two electrodes as it charges and discharges. Several different substances have been utilized as the electrolyte in batteries over the years, with a lithium-ion liquid gaining popularity in recent years.
Although the lithium-ion electrolyte has been instrumental in creating batteries with better storage qualities than its predecessors, it suffers from several limitations. The liquid is highly corrosive, highly combustible, and operates in a limited temperature range. In addition, lithium-ion batteries form dendrites, which are stacks of lithium metal that occur on the surface of the electrodes that reduce the number of energy-carrying lithium ions and, in some cases, short out the battery when they reach the other electron.
Altech continues by noting that a promising new design featuring 4N alumina may alleviate some of the limitations inherent with current lithium-ion battery design. The next generation of lithium-ion batteries are likely to feature a solid-state electrolyte, which significantly reduces the temperature and dendrite problems associated with the liquid electrolyte. Among the top contenders for best solid-state electrolyte material is polyethylene oxide (PEO), which are made from a mixture of lithium salt and a high-molecular weight polymer with lithium-ion coordinating groups.
PEO electrolytes have their own limitations as well, the most significant of which is the low ion conductivity at lower temperatures due to significant crystallization of the polymer. However, Altech cites research showing that mixing in 4N alumina at quantities of between 10 and 15 percent, crystallization temperature is lowered sufficiently to keep the polymer amorphous, allowing it to continue to be conductive of ions at lower temperatures as well. Additionally, the introduction of HPA into the polymer at that concentration increases its strength, improves cycling performance, and reduces the polymer host’s crystallinity, which Altech believes will enhance the desirability of HPA in lithium-ion batteries.
Altech Chemicals is based in Subiaco, Western Australia and is attempting to implement a marketable process for delivering 99.99% (4N) HPA using conventional equipment at a lower production cost than methods currently available. It plans to construct a 4,500 metric ton per annum HPA plant at Tanjung Langsat Industrial Complex, Johor, Malaysia that will use kaolin clay from a company-owned mine in Meckering, Western Australia. The firm is fast-tracking HPA production due to an agreement with Mitsubishi for 100% of its proposed HPA production for ten years. At present, Altech intends to commence project development later this year.