Argonne National Laboratory
Science 101: Batteries
What is a battery?
Batteries power our lives by transforming energy from one type to another.
Whether a traditional disposable battery (e.g., AA) or a rechargeable lithium-ion battery (used in cell phones, laptops, and cars), a battery stores chemical energy and releases electrical energy.
There are four key parts in a battery — the cathode (positive side of the battery), the anode (negative side of the battery), a separator that prevents contact between the cathode and anode, and a chemical solution known as an electrolyte that allows the flow of electrical charge between the cathode and anode.
Lithium-ion batteries that power cell phones, for example, typically consist of a cathode made of cobalt, manganese, and nickel oxides and an anode made out of graphite, the same material found in many pencils. The cathode and anode store the lithium.
When a lithium-ion battery is turned on, positively charged particles of lithium (ions) move through the electrolyte from the anode to the cathode. Chemical reactions occur that generate electrons and convert stored chemical energy in the battery to electrical current.
When you plug in your cell phone to charge the lithium-ion battery, the chemical reactions go in reverse: the lithium ions move back from the cathode to the anode.
As long as lithium ions shuttle back and forth between the anode and cathode, there is a constant flow of electrons. This provides the energy to keep your devices running. Since this cycle can be repeated hundreds of times, this type of battery is rechargeable.
Batteries and the U.S. Department of Energy’s (DOE) Argonne National Laboratory
Argonne is recognized as a global leader in battery science and technology. Over the past sixty years, the lab’s pivotal discoveries have enabled vehicles to travel farther, the grid to be more resilient and secure, and the U.S. energy storage industry to lead the world.
The lab’s research spans every aspect of battery development, from next-generation of materials discovery at the Argonne-led Energy Storage Research Alliance, a DOE Energy Innovation Hub, to multidisciplinary research at the Argonne Collaborative Center for Energy Storage Science, to innovative battery recycling efforts taking place at the ReCell Center, which reduce battery lifecycle cost and U.S. reliance on foreign raw materials.
The lab is also the lead institution for the newly-launched Low-cost Earth-abundant Na-ion Storage (LENS) Consortium, which aims to develop safe, inexpensive, and long-lasting sodium-ion batteries that are made from U.S. abundant materials.
For another take on “Batteries 101,” check out DOE Explains.
How does a lithium-ion battery work?
Lithium-based batteries power our daily lives, from consumer electronics to national defense.
A lithium-ion battery is a type of rechargeable battery. It has four key parts:
- 1The cathode (the positive side), typically a combination of nickel, manganese, and cobalt oxides.
- 2The anode (the negative side), commonly made out of graphite, the same material found in many pencils.
- 3A separator that prevents contact between the anode and cathode.
- 4A chemical solution known as an electrolyte that moves lithium ions between the cathode and anode. The anode and cathode store lithium.
When the battery is in use, positively charged particles of lithium (ions) move through the electrolyte from the anode to cathode. Chemical reactions occur that generate electrons and convert stored chemical energy in the battery to electrical current.
When the battery is charging, the chemical reactions go in reverse: the lithium ions move back from the cathode to the anode.
