Aluminium-Celmet a fix for EV range anxiety?

Japanese engineering giant Sumitomo Electric is reported to be working on a new electrode material with the potential to boost the capacity of lithium-ion batteries by anything from 150 to 300 per cent.

Called Aluminium-Celmet, it looks in cross-section like three-dimensional wire mesh, made up of what the company calls a series of large, “interconnected, open and spherical pores”. The key here is its porosity of up to 98 per cent, maximising surface exposure to the electrolyte flowing around and through it.

This is the latest incarnation of Sumitomo’s proprietary Celmet material, until now made using nickel or nickel chrome alloy. It’s made by a process of electro-conductive coating to plastic foam, with the foam removed by heat once the metal and its nickel plating have set.

Celmet’s benefits have already been found to be numerous. Its porosity gives it strong enough filling, retaining and current-collecting performance, making it ideal for use in lithium-ion and other secondary batteries operating at high charge/discharge voltages. It’s light, it’s highly conductive, resistant to corrosion and easy to cut and stamp into shape. As good as it gets, in other words, for the manufacture of hybrid vehicle nickel-hydrogen batteries.

This latest version retains its high porosity, but it’s lighter, offers superior electrical conductivity and better corrosion resistance, all of which add up to an attractive prospect for next-generation lithium-ion batteries for EVs and other batteries operating at high charge/discharge voltages.

The company says that replacing the aluminum foil used in the positive electrode in conventional Li-ion batteries with Aluminium-Celmet's 3D mesh can boost the positive active per-unit area enough to increase battery capacity by 1.5 to 3 times. That translates into dramatic increases in EV range – an extra 200 per cent isn’t out of the question – from battery packs of similar volume.

As Gizmag points out, that would mean a possible 350 uninterrupted kilometres out of a Nissan Leaf (pictured), or more than 1100 out of a Tesla Roadster. Alternatively, it could also make for reductions in battery volume of 33 to 67 per cent with proportionally greater weight savings and no sacrifice in current range.

And, as Sumitomo points out, EV power packs are only the tip of an iceberg of potential. The technology’s advantages can also go into efficient, small footprint home-use batteries for storing solar and other renewable-sourced power, and for boosting the storage and performance of capacitors with substantial reductions in size.

The company has already set up a small-scale production line in Osaka to accelerate its development.