Posted on February 13, 2017 by Charles Morris
Batteries are becoming more and more important for the technology that powers our daily life. A recent episode of PBS’s Nova, “Search for the Super Battery,” aims to bring the public up to date on some of the advances happening in the battery arena.
Above: A look at lithium-ion batteries (Image: Charged)
The program focuses heavily on the safety aspects of batteries. Host David Pogue has great fun demonstrating the spectacular results when lithium-ion batteries are mishandled. We visit laboratories where researchers are pushing batteries beyond their limits, and again and again, we see batteries bursting into flame or exploding. An uncritical viewer might get the impression that current lithium-ion batteries are highly dangerous contraptions, forgetting that they are in daily use in hundreds of millions of computers, phones and other mundane gadgets - as well as hundreds of thousands of electric vehicles - and that real-world safety issues are rare.
Above: A preview of PBS Nova's Search for the Super Battery (Youtube: Nova PBS Official)
Pogue takes us to a battery production facility where we see the steps that go into making an 18650 cylindrical cell, the industry standard cell that is used to power laptops, power tools - and Tesla automobiles. Thin sheets of metallic material, consisting of carefully crafted compounds, are cut into strips, which will form the electrodes - anode and cathode - and a separator that prevents the two oppositely-charged electrodes from touching. These strips are rolled together just like a baker’s jelly roll, and encased in a metal cylinder, which is filled with electrolyte material.
Above: A quick overview of how lithium-ion batteries work (Youtube: BASF)
Next Pogue takes us to Tesla headquarters in Silicon Valley, where Tesla's Alexis Georgeson explains how thousands of these little battery cells are assembled, together with control circuitry, a cooling system and other safety equipment, to form the massive battery pack that propels a Model S at such ludicrous speeds.
Above: Tesla's Alexis Georgeson charging a Tesla Model S (Image: The Australian)
Pogue also visits the lab of Tufts University Professor Mike Zimmerman, who is working on a battery that uses a solid plastic electrolyte. The electrolyte is the material that bridges the gap between the positive and negative electrodes in a battery. Most current lithium-ion batteries use a liquid electrolyte, but researchers around the world are diligently working on solid electrolytes, which offer a number of advantages. Solid-state batteries can theoretically hold more energy, and they are potentially safer. Unlike current lithium-ion batteries, Zimmerman’s battery can sustain major damage without any risk of fire. We see Pogue gleefully poking a hole in the battery with a pair of scissors, and - look ma, no flames! Zimmerman has formed a company called Ionic Materials to commercialize his technology.
Above: Clip showcasing a battery that refuses to explode (Youtube: Nova PBS Official)
The final segment of the program explains an issue that is probably still unfamiliar to most of the general public - stationary energy storage. Technology that can store massive amounts of energy is becoming ever more important, not only to even out the discrepancy between periods of abundant electricity generation and times of peak usage, but also to integrate intermittent energy sources such as wind and solar with the grid.
Above: PBS Nova clip features stationary energy storage (Youtube: CBS Sunday Morning)
Pogue talks with entrepreneurs who are working on various solutions - some more practical than others - including pumped-water storage and flywheels. Increasingly however, the need for storage is being met by batteries, which are flexible, scalable, and slowly but steadily becoming cheaper. Tesla is a leader in this field - the gigantic battery bank that it recently installed for Southern California Edison in the Los Angeles area was the largest battery storage facility ever built - for a few days, until it was surpassed by another massive project.