Lithium-ion Batteries
Improperly recycled batteries can become toxic waste.
The anode is usually made from a carbon such as graphite, but silicon-carbon is also becoming popular.
The cathode is usually made from cobalt, nickel and manganese.
Inside the battery, the sheets of material that make up the anode and cathode are submerged in a solution that acts as the electrolyte.
Test it out
Tap the diagram for more information and click on the buttons to change a component and see what happens!
Charge the Battery
Turn on the Car
Example calculations
In order to work with Lithium-ion Batteries, electrical engineers need to understand and work with a variety of calculations. Here are just a few:
Cathode (positive) Electrode half-reaction:
CoO2+Li++e    LiCoO2CoO_2 + Li^+ + e^- \iff LiCoO_2
Anode (negative) Electrode half-reaction:
LiC6    C6+Li++eLiC_6 \iff C_6 + Li^+ + e^-
Full reaction:
LiC6+CoO2    C6+LiCoO2LiC_6 + CoO_2 \iff C_6 + LiCoO_2
Energy Density (Wh/kg):
ED=Vnom×AhBattery weight(in kg)E_D = \frac{V_{nom} \times Ah}{Battery \ weight (in \ kg)}
ED=Vnom×AhBattery volume(in m3)E_D = \frac{V_{nom} \times Ah}{Battery \ volume (in \ m^3)}
Power Density (W/kg):
PD=Vo×IoBattery weight(in kg)P_D = \frac{V_o \times I_o}{Battery \ weight (in \ kg)}
PD=Vo×IoBattery volume(in m3)P_D = \frac{V_o \times I_o}{Battery \ volume (in \ m^3)}
Cobalt OxideCoO2CoO_2
Output VoltageVoV_o
Output CurrentIoI_o
Nominal Battery VoltageVnomV_{nom}
Rated Battery CapacityAhAh
Lithium-ion batteries are rechargeable batteries that are used to power many of the devices we use every day. These include our phones, laptops, solar and back-up power systems and, of course, electric or hybrid vehicles.
This type of battery has also been growing in popularity because it is smaller and more powerful than other alkaline batteries, and can be re-charged and re-used for a longer period of time.
So how does it work? A lithium-ion battery is made up of a positive electrode known as a cathode, a negative electrode called an anode, and a separator. The separator is a thin, micro-perforated sheet of material that separates the electrodes, but still allows lithium ions to pass through, moving from one side to the other.
This movement is what creates the electrical current. When the battery is being used, or discharging, ions are released by the anode, and internally move to the cathode. In the outside circuit, electrons will then flow in the opposite direction of the ions, and help power the device by creating the electrical current.
When the battery is charging, the opposite happens. Ions reverse their direction and move from the cathode side to the anode.
Practice Questions
Test your new knowledge on lithiumion-batteries by answering these questions.
1. When a lithium-ion battery is charging lithium ions move from…
2. What is not found inside a lithium-ion battery?
3. If you have a 10kg battery with an average voltage of 12V and 100Amp output, what is its Power Density?
ED=Vnom×AhBattery weight(in kg)E_D = \frac{V_{nom} \times Ah}{Battery \ weight (in \ kg)}