Researchers have made an important discovery to advance rechargeable lithium-ion battery technology. The breakthrough is the in the consistency of a solid electrolyte. The discovery has the potential to increase battery safety and exponentially improve battery life and overall storage capacity.
In general, batteries have three chemical components called reactants. There are two electrodes, the anode and the cathode, and the electrolyte. Electrodes are typically composed of solid chemicals that we commonly call metals. The electrolyte is a liquid chemical that sits between the electrodes. Electrolyte is the medium through which energy flows between the electrodes.
Electrical Energy and Chemical Reactions
A battery does not store electricity, which currently is impossible. Rather, a battery stores electrical energy in the form of chemical energy. When in use, chemical reactions transform the chemical energy into electricity. The electricity flows into a device and the energy powers functionality. An operating battery depletes the reactants as the chemical reactions occur. Functionality persists only as long reactants are available. Eventually, use of the battery depletes the reactants so the chemical reactions are no longer possible and the battery ‘dies.’ But, if it is a rechargeable battery, it is possible to apply electrical energy back into the chemical system. This restores the ability to once again store and discharge electrical energy.
Causes of Malfunction
There are two other causes of battery malfunction. First, liquid electrolyte is flammable and poses a safety risk. The most recent well-known example of burning electrolyte is the Samsung Note 7. Second, during the chemical reactions that create electrical energy, bits of metal accumulate on the electrodes. The accumulated metal bits, dendrites, project outward from the electrodes. If a dendrite ends up touching the opposite electrode, a short circuit occurs and the battery is useless.
However, if the electrolyte is solid instead of liquid, then there is no longer a risk of fire. Also, if it is a particular consistency of solidity, then dendrites cannot form. The pursuit of a solid electrolyte has occurred for almost fifty years. The new research is the result of a fundamental reevaluation about the consistency of the solid electrolyte (wow, look at that, the scientific method in action!).
The previous line of research kept looking at stiffer consistencies to protect against dendrite formation. However, the new research shows that the consistency needs to have more elasticity. This is because stiffer materials can suffer from micro-nicks and –scratches that provide a foothold for dendrite formation. However, a more elastic surface provides degrees of flexibility. Therefore, the surface is pliant at pressure points and does suffer from nicks and scratches. A solid electrolyte would also allow the use of pure lithium electrodes thus further increasing the capacity of the battery. In the end, we have smaller, safer, and longer-lasting rechargeable batteries.
Batteries in the Zombie Apocalypse?
A battery is a spectacular device. They are so common and disposable that the majority of us never give them a second thought. Take a moment and try to identify everything around you at this moment that requires a battery to operate. Computer? Watch? Cell phone? That UPS on your computer system? E-cigarette? Fitbit? Gaming console? Cordless power tools? Car? Lunar explorer? The Mars rover Curiosity or the Juno spacecraft? During the zombie apocalypse, I’m definitely looking for guns, but it’s easy to create weapons out of almost anything. However, I’ll be hoarding batteries like the 90-year old cat-lady hoarding hard candies