It’s a question that everyone asks. Your phone battery seems like it needs to be charged every day or even more frequently as it gets older.
But why does this happen? It appears as if researchers from the U.S. Department of Energy have finally found an answer. Two studies were published by Nature Communications earlier this year, but it seems like the media and the public are only beginning to fully understand the implications this holds for the next generation of smartphones and electric cars.
Most rechargeable batteries, including those in smartphones, are mainly composed of lithium-ion. By studying these chemicals and their behaviors at a basic level, we now understand why batteries seem to degrade as quickly as they do in high power devices such as smartphones. Matt Safford of the Smithsonian boiled down the research and eloquently stated the two main causes:
“The first: microscopic vulnerabilities in the structure of the battery material steer the lithium ions haphazardly through the cell, eroding the battery in seemingly random ways, much like rust spreads across imperfections in steel.
In the second study, focused on finding the best balance between voltage, storage capacity and maximum charge cycles, researchers not only found similar issues with the ion flow, but also tiny accumulations of nano-scale crystals left behind by chemical reactions, which cause the flow of ions to become even more irregular after each charge. Running batteries at higher voltages also led to more ion path irregularities, and thus a more rapidly deteriorating battery.”
So to recap, it looks like structural vulnerabilities and microscopic crystal deposits that build up after every charge are what causes your phone’s battery to get worse over time. Of course they are quick to admit that this is just the tip of the iceberg, with other probable causes of battery degradation that haven’t been discovered yet.
However, the team firmly believes that their research will lead to advancements in not only the phone battery, but also the battery of electric cars. Right now a phone battery lasts about three years before degradation becomes problematic, and electric car batteries last for up to 15 years. If scientists can figure out how to eliminate a lithium-ion battery’s structural vulnerabilities and deposits at the molecular level, our phone battery could last a lifetime, charging as well as it did on day one.
