Lithium Ion Battery Voltage Curve
A Lithium Ion battery is an electrochemical device with an anode and a cathode, separated by a current collector. The positive electrode is usually metal oxide, and the negative electrode is usually made of graphite. The cells are placed in series to create a battery pack that delivers amp-hours.
The energy density of a lithium battery is high. Depending on the cell chemistry, the battery can produce from a few amps to hundreds of amps. This makes lithium batteries more suitable for powering electrical appliances like electric scooters and advanced electric wheelchairs.
A lithium battery's maximum output can be influenced by the voltage and charge of the device. The open circuit voltage, for instance, is a function of the anode and cathode materials used. The Li-manganese chemistries have a nominal cell voltage of 3.70V. The voltage is a function of the anode/cathode materials, as well as the amount of additives.
Among the batteries available today, the Li-ion battery is the most popular because of its ability to deliver large amounts of power. A typical Li-ion cell can produce 7.8 Ah of electricity. The phosphate-based battery has a nominal cell voltage of 3.30V, which makes it incompatible with the usual Li-ion charging algorithm.
A battery's capacity can be determined by its maximum voltage, C-Rate of discharge, number of cycles and other attributes. The shortest route to a rated voltage is through the constant current phase. This phase applies a steadily increasing voltage until the top-of-charge voltage limit per cell is reached.
