German scientists have unveiled a groundbreaking technology for producing silicon fiber-based anodes, poised to enhance the energy capacity of lithium-ion (Li-ion) batteries by up to 250%. This innovation from the Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) can notably improve batteries for electric vehicles, consumer electronics, and renewable energy storages.
Within the FACILE project, which brings together regional partners, researchers proposed using flexible, electrically conductive nonwoven materials as substrates for silicon anodes. Traditionally, lithium-ion batteries utilize graphite anodes, storing about 370 mAh of lithium per gram. Theoretical capacity for silicon (Si) is 4200 mAh per gram, over ten times that of graphite. Yet, silicon swells by 300% when absorbing lithium, causing cracking and device failure.
The new anode design compensates for volume changes, preventing material cracking and delamination during charge and discharge cycles. According to Markus Holzle, head of ZSW, the project’s goal is to achieve battery production with at least 1000 mAh per gram capacity, elevating the anode’s actual energy capacity by at least 250%.
The ZSW team has integrated these new anodes into small test cells to assess their performance. The next step involves analyzing, refining, and scaling up production processes for large battery cells used in electric vehicles. With several pilot production lines capable of making lithium-ion cells with 100 ampere-hour (Ah) capacity, the institute is well-positioned to expedite development.
Developed fiber-based silicon anodes will enable lighter electric vehicle battery packs with increased driving range and more environmentally friendly production.
