In five years, your smartphone could be powered completely differently. Sony has revealed that is developing new sulfur rechargeable battery technology that would replace lithium-ion (li-ion) units. The goal is to have them ready for the market in 2020.
By using sulfur compounds as material for the electrode, the energy density per volume (i.e. the energy stored based on the size of the battery) would increase from 700Wh/L to 1,000Wh/L. Compared to a battery already in existence with the same volume, this sulfur battery could have an increased lifespan by 40%.
As Sony works on the sulfur rechargeable battery technology, two different compounds have emerged: lithium-sulfur (Li-S) and magnesium-sulfur (Mg-S). The Li-S unit uses the sulfur compound for the positive electrode and metal lithium for the negative electrode. Though the compound has a low voltage, the theoretical value of its capacity per weight is high, potentially leading to an energy density higher than 1,000Wh/L.
One of the main issues with this development, however, is the discharge at the negative electrode. When metal lithium is used, the battery can generate dendrites, or lithium deposits. These dendrites can cause a short circuit that leads to heat generation or ignition, which could pose a danger to the user.
Despite difficulties like dendrites, Sony sees this development as promising. Once these units are ready, the first order of business would see these batteries be used in smartphones, and then other applications.
With the large capacity of these batteries, the company would like to see them used in everything from mobile devices to robots. Sony is not the only company pursuing sulfur rechargeable battery development, so it is likely we will be hearing more about the research in the future as manufacturers race to become the first to market.