BATTERY TECHNOLOGY A brief overview of lithium-ion battery technology
Lithium-ion batteries are one of the most widely used types of rechargeable battery, and their dominance continues to grow year-over-year. Here’s a brief overview of a technology that has transcended generations in technology.
In the 1970s, a team of research scientists began working on what would become the lithium-ion (Li-ion) battery, a type of rechargeable battery that would one day power pretty much everything. From portable electronics to electric vehicles, it’s a technology that has well and truly shaped the electronics industry and our world.
Last year, three scientists behind the battery technology—John B. Goodenough, M. Stanley Whittingham, and Akira Yoshino—were awarded the Nobel Prize in Chemistry for their work in developing it. According to the Nobel Foundation, “this lightweight, rechargeable and powerful battery is now used in everything from mobile phones to laptops and electric vehicles. It can also store significant amounts of energy from solar and wind power, making possible a fossil fuel-free society.”
Despite being over four decades old, interest in Li-ion technology and its use in electronics applications continues to grow. Recent estimations say that the market will grow at a compound annual growth rate (CAGR) of 18.16 percent and reach a value of $61.14 billion by 2023, up from $31.36 billion in 2019.
Early Li-ion battery development
In the early 1970s, Whittingham, who at the time was a chemist at Exxon, started exploring the idea of a new battery that could recharge on its own in a short amount of time: a Li-ion battery. While his first attempt worked, it was based on a metallic lithium anode which was found to chemically react with the electrolyte, leading to instability and the growth of lithium ‘whiskers’ (i.e., dendrites) that could cause the battery to explode.
Then in the 1980s, Goodenough, who was an engineering professor at the University of Texas at Austin at the time, had a different idea. He experimented using lithium cobalt oxide as the cathode instead of titanium disulfide. This doubled the battery’s energy potential from 2 V to 4 V.
Finally, five years later, Yoshino, who was working at Asahi Kasei Corporation, developed the use of graphite for the anode. Initially, petroleum coke was used, but graphite was found to be a far better material. The Li-ion intercalated into the layered graphite, providing a huge boost as no free metallic lithium is used in the battery. This made the battery far safer and enabled the first prototype Li-ion battery to be produced.
Together, these three developments led to the Li-ion battery as we know it today.
In 1991, the Li-ion battery was commercialized by Sony and Asahi Kasei Corporation, with Samsung SDI beginning the manufacture of Li-ion batteries at their Cheonan, Korea plant in 2000.
How a Li-ion battery works
Below, we can see the four components of a typical Li-ion battery. On the right is the anode (the negative terminal) and on the right is the cathode (the positive terminal). These are kept apart by a porous separator and an electrolyte.
In the normal operation of a Li-ion battery, positively charged lithium ions (Li+ ions) flow from the anode to the cathode through the porous separator. A corresponding electron current flows through the electrical load from the anode to the cathode. Lithium is used because it’s the cheapest, lightest, and most abundant electropositive chemical element.
This simple technology has proven to be totally transformational. Without it, it’s likely that the digital revolution that we’ve seen over the last few decades—with portable devices leading the way—would not have occurred. In addition, the major progress we’re seeing with electric vehicles would have struggled to take off.
Given that the fundamental structure of the Li-ion battery is the same as that of Alessandro Volta who described and invented the first battery—composed of copper and zinc stacks separated by saltwater—in 1800, the levels of innovation and progress that we’ve seen and continue to see is staggering.