Altech Silumina achieves breakthrough in battery capacity retention

Altech Batteries has confirmed a breakthrough in the development of its Silumina Anodes technology recording an 85 per cent retention capacity after 500 charge-discharge cycles by adding just 5 per cent alumina-coated silicon to graphite anodes. 

The company’s latest Silumina Anodes deliver a charge capacity of 420 mAh/g which far surpasses graphite’s capacity in the range of 230-250 mAh/g. Importantly, Altech’s Saxony pilot plant offers scalability, producing lighter batteries with a longer EV range.

The results, capable of being replicated consistently above 88 per cent retention, highlight process stability and strong scalability potential, with the Saxony pilot plant producing high-quality material for commercial qualification.

Silicon’s ability to store ten times more lithium than graphite offers a leap in energy density, but its 300 per cent expansion during charging has historically caused rapid capacity loss.

Altech’s proprietary alumina-coated spherical silicon mitigates this expansion problem, reducing swelling and maintaining electrode integrity. Starting at 500 mAh/g - a 40 per cent improvement over graphite - the anode retains 420 mAh/g after 500 cycles, equivalent to the initial capacity of many electric vehicle (EV) batteries.

Altech managing director Iggy Tan said: “These latest results mark a genuine breakthrough for the battery industry. Achieving 88.5% retention at 500 cycles with a 5% silicon addition confirms the stability of our Silumina Anodes™ process. Our Saxony facility continues to deliver consistent results, validating the technology and scaling methods. Altech’s breakthrough positions us at the forefront of next-generation anode materials, unlocking longer lasting, higher-capacity lithium-ion batteries.”

The significant  performance upgrade, offering the potential for increased EV range, addresses a major point of resistance to potential  buyers with either lighter battery packs or smaller packs, while for grid storage, it could lower footprints and costs.

The process involves coating submicron silicon with a nanolayer of alumina, then spherising it to fit seamlessly within graphite anodes, allowing expansion without structural damage. 

The Saxony pilot plant, adjacent to Altech’s planned commercial site, is producing consistent batches, while trialling various silicon sources to ensure reliable supply chain flexibility. 

The breakthrough puts Altech in the frame to meet growing demand for high-performance, sustainable lithium-ion batteries, paving the way for next-generation cells with improved capacity, range and lifespan.

As Altech scales up at its Saxony pilot plant with what could be termed a virtual “holy grail” of anode materials - without compromising durability and enhancing safety – the company’s technology could redefine EV and grid storage standards and that is bound to draw keen interest from manufacturers and investors.

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