Elkem develops composite to increase energy storage capacity in batteries

The transportation sector accounts for 14 per cent of global greenhouse gas emissions. An increase in electric vehicles (EVs) will help to cut emissions, but the lithium-ion batteries used in EVs today have limited energy storage capacity and cannot fully satisfy future needs.

A key component of lithium-ion batteries in EVs is the anode, composed mainly of graphite, which provides stable energy storage but with a limited energy storage capacity that is already close to the theoretical maximum.

Replacing the graphite with silicon can solve this problem, as the theoretical storage capacity of silicon is about 10 times higher than graphite. The challenge with a silicon-based anode, however, is that silicon expands massively during charging and contracts when discharging, thus causing disintegration. This leads to poor cycle performance and limited battery life.

Elkem produces both graphite and silicon, two key materials for battery storage. The company is developing a composite combining graphite and silicon, in which the amount of silicon can be increased gradually to increase the energy density of the batteries. If successful, the composite will enable producers to increase energy storage capacity in the same space or to store equivalent amounts of energy in a smaller space.

Elkem is currently focused on technology development in collaboration with potential customers, developers and institutes. If successful, using silicon in batteries will significantly increase energy density and reduce charging time. Results to date show that a battery with a silicon/graphite anode could do more than 1 000 charge cycles.

Elkem’s project has so far resulted in one patent and two patent applications. Elkem currently produces and supplies commercial amounts of speciality silicon, Silgrain®e-Si, from its Bremanger plant. The company’s production process gives Silgrain®e-Si a considerably lower environmental footprint than comparable silicon materials.

By 2030, it is estimated that 22 to 30 per cent of new light vehicles sold will be electric. The total lithium-ion battery market is estimated to grow from 120 GWh in 2017 to over 800 GWh in 2025.

Elkem is uniquely positioned to supply solutions to the battery industry and the EV market, as the company already provides products to the automotive industry and, increasingly, to the EV market. Elkem’s core focus areas are graphite for anodes, silicon for anodes, and silicone solutions for battery packs, modules and other EV applications.