When folks think of electric vehicles, they associate the driving force with lithium batteries. Not quite so true for us. We are more interested in seeing if we can get green hydrogen fuel cells or some other metal based battery. Admittedly, because, here in America, we don’t have easy access to copious quantities of lithium- and because of the environmental issues with recovering lithium from the earth.
So we were pretty excited when we ran this article by Drs. M. Wu [postdoc], L Xu, CP Yang, M Hong, C Mingjin, BC Clifford, S He, S Jing, and L Hu (all from U Md), Y Zhang and Y. Yao (both from the U Houston),
What’s the article?
A sustainable chitosan-zinc electrolyte for high-rate zinc-metal batteries, as published in Matter.
For starters, this batter is based upon zinc, which is cheaper and more abundant than lithium. Oh, yeah- it’s also charges and discharges more rapidly than does lithium. But, the problem is that zinc batteries tend to form spindles (called dendrites) that diminish the battery’s capability- or even let them short circuit. (By the way, dendrites are also a problem for lithium batteries- which is why they occasionally catch fire.)
So, incorporating these batters in a gel electrolyte (comprised of chitosan- which is obtained from crab shells) solves this issue. Moreover, since it is biodegradable and easily obtainable, this makes the battery a true “green machine”. Moreover, the gel is capable of bonding water, so there is less free water in the electrolyte, which keeps those dendrites to a minimum. (Chitosan contains hydroxyl and amine groups that develop hydrogen bonds with water; this reduces the free water in the electrolyte.).
The Maryland team recovered the chitosan from crustacean shells, placed it in solution (on a polyethylene terephthalate substrate), and then immersed the whole mess in a zinc-saturated sodium hydroxide solution.
The team claims the battery yields an energy efficiency of some 99.7%- after 1000 cycles! And, it has a current density of 50 mega-amperes/cm2 for 400 h. Moreover, the battery is not flammable (but does shrivel when exposed to an open flame). And, if we bury the battery in dirt, it should decompose in some 5 months time. Oh- and the cost? And it should cost out about $ 46.50 per kilogram (That makes it comparable in price to other batteries.)
Things are looking up for our electric vehicle batteries.
Sounds interesting but I think I’m too old to comprehend driving cars with batteries instead of fuel. I may be in the old folks home when it’s all battery and won’t have to worry about driving. LOL
OH, Martha, I beg to differ with you. I bet you will be using an EV sooner than you think- as internal combustion engine vehicles cease being produced
Hi Roy,
That is great news. Does that mean there is less lead in the battery too?
Is this technology likely to find its way into other battery forms like AA and AAA?
Lead is more likely to be found in “dry cell” batteries (and even there not too often). THe high tech batteries tend to avoid lead.
I don’t think the AA and AAA batteries will use this technology until the price drops- we expect our dispoable batteries to be dirt cheap- these hydrogels and lithium varieties are significantly more expensiv, Doug.
I would still be hesitant to purchase an electric vehicle (assuming we could afford one) right now. I have some environmental concerns (everything has an environmental cost and I’m a big believer in “unintended consequences”) about these vehicles. I am also a big believer (as if it was a belief and not a fact!) in climate change moving faster than anyone expected so this is very good news.
I, too, am reticent about obtaining an EV. Both because of the charging issues- and secondly because we have not yet upgraded our electric grid, which means most of the EV will be powered by fossil fuels… Not quite what one would think.