Introduction to Lithium-ion Batteries
The field of battery chemistry has made tremendous progress over the past decade. This enables many new applications to benefit from the use of batteries, including the electric vehicle industry. Lithium-ion batteries are the star of recently developed chemistries.
Characteristics of lithium-ion batteries
These are some of the characteristics of lithium-ion batteries:
Li-ion batteries operate at a higher voltage (3.7V nominal) than other common chemistries (1.2V for NiMH for example). This makes them suitable for more applications because fewer batteries are needed to reach a given voltage.
While other battery chemistries do not require a battery management system, Li-ion batteries require it to operate in safe conditions. In essence, a BMS is an electronic circuit that measures the voltage and other parameters of all or more cells in a battery. An algorithm in the electronic device determines whether a particular battery's voltage needs to be regulated by the same device. The fact that Li-ion batteries require a BMS is a small disadvantage compared to other chemistries, however, for high-performance or high-capacity applications, all chemistries require a BMS, so this is no longer a disadvantage.
Li-ion batteries have a lower self-discharge rate than other battery chemistries. Lithium-ion batteries will retain most of their capacity even months after their build date. This is a big advantage compared to other chemistries such as NiMH or NiCd which have a self-discharge rate of around 1%-5%.
