Friday, March 10, 2017 by Tracey Watson
An electric car is a vehicle that is propelled by an electric motor, most often using energy stored in rechargeable batteries. Though the general public’s perception is that these vehicles are better for the environment than conventional petrol or diesel vehicles, that is not necessarily true. Nevertheless, a recent breakthrough in battery technology could propel us closer to a future in which far more electric vehicles take to the road.
There are several problems that dog electric vehicles, making them slow to take off among consumers; many of these issues center around the batteries used to store the energy that powers the vehicles. Among these is the high cost of the batteries; the fact that they have to be recharged often, and when they do it is time-consuming; and the fact that the batteries do not perform well in cold weather.
Two scientists at the Cockrell School of Engineering at the University of Texas, Austin: Professor John Goodenough, 94, and senior research fellow Maria Helena Braga, have been working on a solution to the problem. As the co-inventor of the lithium-ion battery, Professor Goodenough is certainly well placed to do so.
The team has created the first all-solid-state battery that they hope will provide safer, longer-lasting batteries for mobile devices and electric cars. The new battery will charge more quickly and cost much less than the batteries currently in use.
The new technology was revealed in a paper published recently in the journal Energy & Environmental Science.
Among the benefits of the new battery are the fact that it is non-combustible, has a long life, charges and discharges quickly, and has high volumetric energy density (which to the layman means it packs a lot of energy in a small package). All of these advantages combine to mean more miles driven between battery charges. And that recharging occurs at a much faster rate, too.
“Cost, safety, energy density, rates of charge and discharge and cycle life are critical for battery-driven cars to be more widely adopted. We believe our discovery solves many of the problems that are inherent in today’s batteries,” said Goodenough.
The all-solid-state battery carries a significant safety advantage too. While lithium-ion batteries use liquid electrolytes to transport lithium ions, the new battery uses glass electrolytes instead. If a battery cell charges too quickly, dendrites – known as metal whiskers – can form, causing a short circuit and possibly leading to a fire or an explosion. The glass electrolytes remove this risk.
Those glass electrolytes solve another problem, too. While other batteries cannot operate well in very cold conditions, the new battery’s glass electrolytes work well even at -20° Celsius (-4° Fahrenheit).
And there’s a third benefit to the glass electrolytes: Lithium can be replaced by inexpensive sodium, cheaply and easily extracted from seawater.
Indeed, getting the cost of electric cars’ batteries down is extremely important, because they are traditionally one of the most expensive parts of such vehicles. Though their costs have been falling steadily – from a global average of $1,000 per kilowatt hour in 2010, to about $350 today – manufacturers have stated that the price would have to drop below $150 per kilowatt hour before electric vehicles could become commercially competitive.
The jury is still out on the environmental impact of electric cars. After all, the electricity that charges the battery has to come from somewhere, and in the U.S., that still most commonly involves the burning of carbon. (RELATED: Are you concerned about the environment? Stay up-to-date with the issues at Environ.news)
As Ken Caldeira of the Carnegie Institution for Science explains, “Unfortunately, when a wire is connected to an electric vehicle at one end and a coal-fired power plant at the other end, the environmental consequences are worse than driving a normal gasoline-powered car.”
Nonetheless, with the invention of the all-sold-state battery, a future where are roads are filled with electric cars is one step closer to being reality.
Sources for this article include: