Around us wherever we are and wherever we stand we will definitely find devices that are equipped with rechargeable batteries and this has become a habit for us. However, despite the convenience of reusing our devices over and over with intermediate charges, the batteries of these devices have a relatively short lifespan. A new study has identified why.
Many things that we have at home, at work or carry around all the time even on the go, such as tablets, mobile phones and PCs, rely on recharging their batteries. From technical analysis, we know that inside a lithium-ion battery, two electrodes store lithium ions, positively charged at the anode and negatively charged at the cathode. An electrolyte inside the battery allows ions to move from the anode to the cathode. This movement starts a chemical chain that leads to the release of charge-generating electrons.
But new research from a team at Stanford University suggests that along with lithium ions, “unwanted passengers” are also being moved to the cathode. Hydrogen protons and electrons are also detached from molecules in the electrolyte. These build up at the cathode, meaning the lithium ions are not able to carry the charge as efficiently. The power these batteries store erodes over time.
This constant leakage of hydrogen is caused by a set of chemical reactions. Gang Wan, a physicist and chemist at Stanford University, told the Science News “Even if you don’t use the battery, it loses power.”
Hydrogen is a tiny, ever-present element that is difficult to detect. To reveal the role it played in the disabled batteries, Wan and his team had to replace the hydrogen with an XXL variant. This is deuterium, an isotope of hydrogen that holds a neutron and a proton, compared to hydrogen’s single proton.
Using mass spectrometry analysis and X-ray imaging, Wan’s team tracked the deuterium as it moved through the battery. This showed that hydrogen was the driving force in reducing battery charge.
In short, this study opens a path to improving batteries by targeting the unwanted chemical changes that these leaking hydrogen molecules produce. But it can also cause some concern for battery designers. Wan’s research suggests that in the race for more powerful batteries, engineers may be increasing the chance that cathodes will run into loose hydrogen and shorten battery life.
Source: myphone.gr
