Batteries took over the modern world without changing all that much.
A smartphone, by comparison, has far less in common with the mainframe computers that preceded it. Same goes for the Tesla Model 3 and the Ford Model T. But lithium-ion technology used in today’s batteries has sustained decades of exponential growth—moving from gadgets to electric vehicles, and even spawning a few billionaires along the way—without major changes to its structure since Sony first commercialized the technology in 1991.
That’s not because chemists haven’t tried. It’s just that developing new materials that perform to industrial standards is a very hard problem.
All batteries have four components: two electrodes (anode and cathode), a liquid electrolyte that helps ions move between the electrodes, and a separator to keep the electrodes from coming in direct contact with each other and preventing fires. When a battery is charged, ions flow from the cathode to the anode. When it’s discharged, the ions reverse course.
As the world moves to rapidly cut greenhouse-gas emissions, the race is on to plug more things into ever more powerful batteries: power grids, trucks, ships, and even airplanes. The innerspace of this crucial technology is finally poised to see dramatic changes, with a number of secretive startups promising breakthroughs. QuantumScape Corp. claims to have created a new battery material that would allow electric cars to travel further and charge much faster—and as a result the startup has a valuation that’s ranged between $13 billion and $20 billion in recent weeks, even without any revenue in sight. Its rivals, including giants like Samsung and Panasonic, are also chasing next-generation batteries.
Before we reach the battery future, it’s important to understand the physical evolution of today’s lithium-ion tech. Billions of people experience phones with faster recharging and cars with longer range, but few of us can explain what’s behind these improvements. It’s a story of tweaks: small efficiencies in manufacturing, small improvements in materials, and small gains in performance.