It’s probably safe to say that just about everyone is impressed with the incredible performance offered by lithium-ion batteries. They make our cell phones and laptops viable for real-world use and will be powering just about every electric vehicle on the road. These batteries do have one problem however: they sometimes catch fire. That’s not good. Fortunately, scientists at Cambridge University think they’re on the road to solving this problem - a new technique allows them to “see” the chemistry at work inside batteries.
The reason lithium-ion batteries do catch fire involves tiny lithium particles that form fibers known as dendrites. Over several charge/discharge cycles, these dendrites can accumulate on the battery’s carbon anodes. Once that happens, short circuits can occur, resulting in rapid overheating and combustion. Scientists have previously been able to study the principles of dendrite formation using theoretical models and microscopes, but had not been able to quantify the amount of dendrites formed... until now.
Using Nuclear Magnetic Resonance (NMR) spectroscopy, the Cambridge scientists were able to watch the chemical reactions actually taking place within a 1-cm long battery enclosed in an aluminum bag. While they have yet to figure out a way of dealing with the dendrites, it’s definitely a step in the right direction.
"Fire safety is a major problem that must be solved before we can get to the next generation of lithium-ion batteries and before we can safely use these batteries in a wider range of transportation applications. Now that we can monitor dendrite formation inside intact batteries, we can identify when they are formed and under what conditions,” wrote Professor Clare Grey of the Department of Chemistry. “Our new method should allow researchers to identify which conditions lead to dendrite formation and to rapidly screen potential fixes to prevent the problem."
The research was recently published in the journal Nature Materials.
Anyone heard of Lithium-Sulphur yet?
Oxis Energy says, \"Sulphur represents a natural %u2018cathode partner%u2019 for metallic Li and a Lithium-Sulphur couple has theoretical specific energy in excess of 2700Wh/kg, which is nearly 5 times higher than that of Li-ion.\"
Although the Lithium-Sulphur or Li-S battery will extend the use of Lithium and is a great step forward for the safe use of Lithium, there is a very small, cheap and easily obtainable supply of Lithium in the world. After that, it will be processing rock to get to the Lithium. This will be the end of cheap Lithium and the end of relatively cheap batteries across the board.
Read this report entitled \"The Trouble With Lithium\" for some insight into how small the cheap deposits are and how few years there are if production of electric cars and other Lithium products continue at the current projected rate. This report also strongly suggests the use of Zinc, in a Zinc-Air battery or fuel cell, is a cheaper, safer material that is completely sustainable. http://www.meridian-int-res.com/Projects/EVRsrch.htm and http://www.meridian-int-res.com/Projects/Lithium_Microscope.pdf
Zinc-Air technology is well on its way to surpassing all Lithium products. It also boasts of several times the specific energy of Lithium without all the associated negatives and expense. Zinc-Air batteries can be used with easily replaceable sheets or even incorporated into the existing gas station infrastructure using a Zinc imbedded slurry. Drain the used slurry, fill the tank with new slurry and have the used slurry reconditioned to be used again, quite possibly on site at each fuel station. Is there a more simple idea to replace gasoline and diesel?
Zinc seems to be the best of all the battery/fuel cell options now on the drawing board. In the meantime, Lithium-Sulphur would seem to be the latest and best option to replace current battery technology for everything Lithium powered.