Berlin Scientists Boost Green Battery Tech Performance
An outer protective layer shields the porous core of the carbon anode from unwanted deposits, thereby increasing the battery's performance. © BAM
Berlin researchers have made a significant leap forward in sustainable battery technology. Scientists at the Federal Institute for Materials Research and Testing (BAM) have developed an innovative anode design that dramatically improves the performance of sodium-ion batteries, bringing them closer to matching their lithium-ion counterparts.
According to information from the BAM press release, the breakthrough addresses a critical challenge that has long hindered sodium-ion battery development: massive energy losses during the first charging cycle. Traditionally, these batteries lose up to 82 percent of their capacity during initial charging, making them far less efficient than lithium-ion batteries, which typically maintain over 90 percent efficiency.
The culprit? A chemical reaction between the anode and the electrolyte creates a protective film that consumes sodium ions needed for energy storage. While this film is necessary to protect the anode, it essentially wastes valuable storage space.
The BAM team's solution is elegantly simple yet highly effective. They developed a core-shell design that coats porous hard carbon with an ultra-thin protective layer. This layer acts as a selective filter, allowing sodium ions through while blocking problematic electrolyte molecules.
"We realized that large storage capacities and efficient film formation cannot be achieved with sodium-ion batteries using a single material," explains Tim-Patrick Fellinger, BAM expert for energy materials.
The results are impressive. The new design achieves 82 percent initial efficiency compared to just 18 percent without coating. Even better, the technology uses activated carbon, an inexpensive and environmentally friendly material, making it economically viable for mass production.
The research, published in Angewandte Chemie, will continue at the Berlin Battery Lab, a collaboration between BAM, Helmholtz Zentrum Berlin, and Humboldt Universität Berlin. This facility provides industry partners with a unique platform to transform battery innovations into market-ready products, strengthening Berlin's position as a hub for sustainable technology development.