The main problem with modern lithium-ion batteries is that they "wear out" over time. That is, the more charge-discharge cycles they survive, the less their efficiency or, in other words, the ability to retain electrons becomes. But it looks like the situation will change dramatically in the near future, because scientists at Stanford University have developed a self-healing battery.
Over the past several years, many scientists have worked to increase the density of lithium-ion batteries while reducing their weight. The results were different. But one of the indisputable achievements was the use of silicon in the cathode of the battery, which made it possible to pass a much larger number of electrons through it. Filling with electrons, silicon expands up to 300%, after which it contracts back with the release of electrons. This process inevitably leads to splitting of the material.
The self-healing polymer, invented by Wang Chao of Stanford University and Hui Wu of Beijing Tsinghua University, does not actually stop cracks from occurring, but simply repairs them instantly. The researchers deliberately weakened several atomic bonds within the polymer so that they break easily, but at the same time are also easily restored chemically.
"We found that silicon electrodes are 10 times more effective when coated with a self-healing polymer that repairs any cracks in a matter of hours." Says Professor Zhenan Bao of Stanford, whose team helped develop the polymer.
Currently, the electrodes invented at Stanford only support 100 charge cycles without damaging silicon. In the very near future, the team plans to increase their productivity up to 500-3000 cycles.