Battery 'Sponge' Made from Foam-Like Copper
A new way to make batteries could boost their power and extend their useful lives.
The humble battery is crucial for technologies ranging from consumer electronics to electric vehicles. But for all of its necessity, it still has major limits. Batteries still take too long to charge, are full of toxic chemicals and typically last just a few hundred cycles. After that, it's the landfill.
Battery Company wants to change that by building a battery that has a three-dimensional internal structure, allowing them to suck up energy faster and extend their lifetimes. The design is the brainchild of Amy Prieto, a chemistry professor at Colorado State University.
Ordinary batteries are made in layers: the part that provides positive charge, called a cathode, the negatively charged part, called the anode, and the electrolyte between them which is usually an acid. The electrolyte allows electrons to move between the cathode and anode. The layers are either flat, as in a phone battery, or rolled up, as in a AAA for the remote.
The problem is that this design only allows electrons - the current - to move from the side of the anode in contact with the electrolyte to the cathode. That provides fewer pathways for the electrons to move, and limits how many can do so, like cramming a crowd of people into a room and only opening the doors on one side. As a result the battery takes a while to charge and loses energy faster.
Prieto's design does something different: the cathode and anode are like a sponge, with lots of holes. So instead of a solid block, the battery has loads of surface area inside. That allows the electrons to move more easily because they have more points of contact. In the room analogy, it's like opening up the exit doors on all four sides, allowing the people to leave faster.
The Prieto batteries are made with copper. The copper, which takes on a foam-like structure, is then coated with the negative electrode material. That in turn is coated with the electrolyte, which is a solid instead of a liquid. The leftover space is filled with the cathode, which is initially a kind of slurry that then hardens into place.
The chemicals used are non-toxic - one component is citric acid as opposed to stronger ones such as the sulfuric acid used in car batteries. The company says they can get it to charge quickly and do so thousands of times, though testing continues and it will be some time before a working version hits the streets.
Credit: Prieto Youtube Screengrab