The performance of lithium batteries has been gradually broken through

The LiJian Technology team integrated molecular pulleys (called polyrotaxanes) into battery electrode binders, including adding polymers to the battery electrodes to attach the electrodes to metal substrates. The rings in polyrotane are screwed into the polymer skeleton and can move freely along the skeleton.

The rings in polyrotane can move freely with the volume change of silicon particles. The slip of rings can effectively keep the shape of silicon particles, so that they will not disintegrate in the continuous volume change process. It is noteworthy that even crushed silicon particles can remain coalescent due to the high elasticity of polyrotane adhesives. The function of the new adhesives is in sharp contrast to that of the existing adhesives (usually simple linear polymers). The existing adhesives have limited elasticity and therefore cannot firmly maintain the particle shape. Previous adhesives can scatter crushed particles and reduce or even lose the capacity of silicon electrodes.

The author believes that this is an excellent demonstration of the importance of basic research. Polyrotaxane won the Nobel Prize last year for the concept of "mechanical bonds". "Mechanical bonding" is a newly defined concept that can be added to classical chemical bonds, such as covalent bonds, ionic bonds, coordination bonds and metal bonds. Long-term basic research is gradually addressing the long-standing challenges of battery technology at an unexpected rate. The authors also mentioned that they are currently working with a large battery manufacturer to integrate their molecular pulleys into actual battery products.