Zinc Ion Battery
Zinc ion battery – Korean researchers have developed a bateria de íons de zinco with a water-based electrolyte – the electrolyte is the medium that allows ions to travel back and forth during use and recharging.
One of the biggest deficiencies of lithium-ion batteries is in their organic electrolyte, which is highly flammable, leading to drastic failures, fires and even explosions.
To use water as an electrolyte, Sangyeop Lee and colleagues at Pohang University of Science and Technology added a protective polymer layer to prevent corrosion of the electrodes.
As an added benefit, the aqueous electrolyte has increased the stability of the zinc anode (positive electrode), improving the electrochemical stability of the battery, meaning they will last longer.
Multifunctional layer
Zinc ion batteries have been researched for a long time, including aqueous electrolyte ones, but the growth of zinc dendrites and unwanted reactions on the surface of the electrodes greatly slows the flow of ions from one electrode to the other, decreasing the energy density. and battery life – dendrites are needle-shaped deposits of Zn that form on the anode during the use/recharge cycle.
Lee and his colleagues solved this by coating the zinc anode with a protective layer of block copolymers, macromolecules composed of two or more different polymer chains joined by covalent bonds. This new layer is elastic and extensible, supporting volume expansion during battery charging and discharging.
In addition, the protective polymer layer homogenizes ion scattering and suppresses dendrites growth, contributing to a long anode life. The coating also improves electrode stability by suppressing unnecessary chemical/electrochemical reactions in the electrolyte on the electrode surface.
Zinc-based batteries offer some key advantages over lithium-ion batteries, including low cost and the fact that they do not catch fire or explode. Kilo for kilo, batteries from zinco-ar can potentially store five times more energy than than lithium-ion batteries, while zinco -nickel produce relatively high voltages, which is useful because few cells are needed to power a device.
