A Quantum Leap for Magnesium-Carbon Batteries

Magnesium-carbon dioxide (Mg-CO₂) batteries have long promised a tantalising dual benefit: storing energy while simultaneously scrubbing greenhouse gases from the atmosphere. Yet, the technology has historically been hamstrung by sluggish kinetics and poor reversibility. The chemical reaction simply demanded too much energy to get going, often resulting in dense, stubborn deposits of magnesium carbonate that choked the system.

Now, researchers have circumvented these classical limitations by exploiting the peculiar physics of the quantum realm. By introducing a homogeneous catalyst known as TEMPO, the team facilitated electron transfer via quantum tunnelling. Rather than forcing electrons to surmount a formidable energy barrier, this mechanism allows them to effectively ‘ghost’ through it, initiating carbon dioxide reduction at significantly lower voltages.

This subatomic sleight of hand fundamentally alters the battery's chemistry. Instead of the problematic carbonate, the reaction now yields flower-like magnesium oxalate structures, which are far easier to manage during recharging. The results are striking: the system achieves a discharge voltage of 1.1 volts and maintains stability for over 450 hours—the finest performance recorded for such a system to date. By rewriting the reaction pathway, we may finally be closing in on a viable method to turn atmospheric carbon into a reliable power source.