Swedish start-up launches reusable nickel metal hydride battery

Nilar International has started production of the reusable ReOX battery in its Swedish factory. The natural ageing process of this battery can be reversed and it is said to be able to run at least three times at full capacity.

Nilar International AB, a Swedish supplier of energy storage systems, has started production of the reusable ReOx battery. This battery simply needs to be refilled with gas to restore its original capacity.

The manufacturing activity comes after Nilar International received an order from Swedish renewable energy company Enequi.

Nilar said, "The order, which includes a total of 800 cells and associated software, will be used in 100 of Enequi's QuiPower Storage smart energy storage units."

The battery consists of ten cells, each containing a positive electrode, separator and negative electrode. All cells are stacked together horizontally with a double metal plate in between. The outer plate acts as a collector for all the cells in the assembly and has a 10% bulk density advantage.

The energy storage system is based on a nickel metal hydride (NiMH) electrolyte that provides ionic conductivity in the cells and has a limited footprint. The electrolyte is renewable and is claimed to have excellent ionic conductivity over a wide temperature range.

Nilar International developed the positive and negative electrodes of the device using patented dry powder compression technology and uses a separator as an electrolyte reservoir. It also uses a double-layer plate to seal the cells and provide electrical contact points between the individual cells.

The company says: "Nilar uses a bipolar design that allows the current to be directed perpendicular to the electrodes and the surface of the bilayer plate, which allows the entire bilayer plate area to be used for current transfer between the cells. This significantly reduces resistance and optimises the uniformity of current distribution on the bilayer board and electrode surfaces."

In the proposed system configuration, each battery pack contains up to 12 components and each component consists of 10 cells. The battery packs have a maximum nominal battery voltage of up to 600 volts DC.

The company says the batteries are also easily recyclable and safer.

The main constituent active material is nickel, which can be easily recycled without loss of quality, and any residue is sent to the metals industry for reuse," says Oldmark. Due to the chemical stability of the non-flammable water-based electrolyte used in the Nilar battery, there is no exothermic reaction between the electrodes. Unlike many other batteries, Nilar batteries are unlikely to self-detonate or even short-circuit internally. There is no risk of heat propagation even if the cells are heated up one by one."