The CObalt-free Batteries for FutuRe Automotive Applications (COBRA) project, a European consortium of 18 partners from the automotive industry and research institutions, has designed a complete cobalt-free lithium (Li)-ion battery system for electric vehicles.

Cobalt is a widely used component in Li-ion batteries and serves to improve device durability, but dependence on its use is deemed problematic due to its anticipated scarcity and associated supply chain risks. The new battery chemistry relies on a Li-rich nickel and manganese oxide cathode in combination with a composite anode based on nanometer silicon and graphite as active particles. The inclusion of treated wood and recycled aluminum have reduced external weight by 30% compared to other batteries.

Source: COBRA

This next-generation COBRA technology incorporates a novel battery management system in a 400 V power demonstrator consisting of 96 cobalt-free Li-ion cells that integrates wireless communications within the battery system, new sensors and advanced algorithms. The communication link relies on optical signals, making it immune to electromagnetic interference.

At the battery cell level, a set of smart sensors measures temperature, swelling (strain gauge), voltage and impedance while also performing passive balancing. At the module level, a pressure sensor detects venting episodes, and a laser-based gas sensor located at the battery pack level detects any gas formation within the pack. Combined, these measurements enable a charge management control to compute the optimal charging profile, minimizing degradation effects such as Li plating.