Safety Feature Reduces Fire Risk from Li-Ion Batteries

March 12, 2019 by Scott McMahan

Ecovolta, a Swiss battery system manufacturer, is introducing a new safety concept in its lithium-ion batteries. According to the company, the new safety concept has been proven to reduce the risk of battery fires and cell explosions in e-mobility applications.

To achieve this safety improvement, Ecovolta employs cell junctions made of cold strips of electrolytically-plated nickel. These cell junctions automatically disconnect faulty cells from the rest of the battery pack when the current rises.

From March 12-14, 2019, Ecovolta will showcase the new battery packs for the first time at the Energy Storage Europe exhibition, booth D04 in hall 8b.

Cell Junction Serves as Reliable Fuse

In the case of mechanical damage to a battery pack, a high current initially flows through the affected region and the temperature rises locally. In conventional battery solutions, the temperature rise affects the cell idirectly. Its material can expand rapidly, which could lead to explosions and battery fires.

However, with Ecovolta battery packs, mechanical damage results in the temperature rising locally at the cell junction. This junction then melts, separating the damaged cell from the intact components. In this way, the rest of the pack remains functional, and only its capacity sinks as the capacity of the separated cell is lost. The company confirmed this in numerous tests.

The new safety concept is incorporated into all Ecovolta traction batteries. This safety feature allows capacities ranging from 10Wh to several hundred kWh and voltages of 12V up to 600V as well as any desired battery shape.

The concept is also used in Ecovolta's evoTractionBattery. The standardized traction battery achieves energy densities of 200Wh per kilogram without active cooling.

"This ecovolta concept offers e-mobility suppliers a battery solution that makes the highest safety standards economical even for small and mid-sized vehicle series," says ecovolta CTO Paul Hauser.

The concept was made possible by a license from H-Tech AG, located in Schaan, Liechtenstein, which Ecovolta uses to produce its battery systems.