Angewandte Chemie International Edition is credited (2023). 10.1002/anie.202303616 is the doi
The energy density of lithium-ion batteries is increased by an ultrathin braided wire in the electrode core, according to research published in the journal Angewandte Chemie International Edition. Such batteries might be used to charge cellphones and other electronic gadgets while we are wearing them, or they could be integrated into useful textiles. In place of a single continuous wire, the innovative braided current collector shape enhances ion movement within the electrode, raising charge density.
Before fiber batteries can be utilized to power tents, functional clothes, and other devices, there is a difficulty that must be resolved. This is because, especially in long fibers, the energy density is far too low to be of any use. It has since been revealed by Huisheng Peng and a group of researchers at Fudan University in Shanghai, China, that this issue might be resolved by modifying the electrode’s current collector.
The group chose to use a braid composed of several, considerably thinner metal threads in place of the current collector, which is a continuous, thin metal wire inside the graphite electrode. They unraveled a number of incredibly thin metal threads from spindles to create the braid, which they then braided into a center thread. Graphite was then applied to the entire braid electrode.
By interacting with the graphite, the novel braided current collector increased the energy density while being just as stable as the continuous wire. According to the scientists, “The designed braiding structure leads to channels filled with active materials, reducing obstruction to lithium ion transport and increasing loading capability of active materials.”
Tests were conducted to confirm this higher energy density: a woven tapestry with 40 one-meter-long FLIBs with braided current collectors was created. The standard FLIB design, which uses a continuous current collector wire, could only charge a smartphone to 52%; in contrast, this FLIB-based textile was able to charge a smartphone from 30% to 57%.
This improvement in efficiency was made possible by a comparatively straightforward modification to the current collector’s design. This is especially crucial for long fiber batteries, which need to be lightweight, stable, and strong.