Most battery-powered devices, from smartphones and tablets to electric vehicles and energy storage systems, rely on lithium-ion battery technology. Because lithium-ion batteries can store a significant amount of energy in such a small package, charge quickly, and last long, they have become the battery of choice for new devices.
How Do Lithium-Ion Batteries Work?
- Lithium is stored in the battery’s anode, the positively charged electrode, and the cathode, which is the negatively charged electrode.
- A liquid electrolyte, or separator, transports positively charged lithium ions between the anode and cathode, the movement of which helps create free electrons in the anode.
- As a result, a charge is built up at the battery’s positive current collector, which flows through the device to the battery’s negative current collector.
- When powering the device, the anode transfers lithium ions to the cathode, and when charging, the cathode returns them.
While lithium-ion batteries have come a long way in the past few years, especially when it comes to extending the life of a smartphone on a full charge or how far an electric car can travel on a single charge, they’re not without their problems. The biggest concerns — and a major motivation for researchers and startups to focus on new battery technologies — are related to safety, specifically fire risk, and the sustainability of the materials used in producing lithium-ion batteries, namely cobalt, nickel, and magnesium.