Lithium-ion: Li-ion batteries are rechargeable batteries often used in portable applications, such as smartphones and laptops. Because they have a high energy density and low self-discharge rates, Li-ion batteries have a long shelf life and charge quickly.
Figure 7: Discharge curve comparison of Lithium-ion and Lead-Acid battery As we can see, a lithium-ion battery tends to maintain a constant output voltage throughout its discharge, but a lead-acid battery loses voltage practically linearly and more quickly.
Online parameter identification methods for Li-ion battery modeling. A moving window least squares method is proposed to identify the parameters of one RC ECM in , but one limitation is the length of the moving window is not fully discussed.
The increasing adoption of batteries in a variety of applications has highlighted the necessity of accurate parameter identification and effective modeling, especially for lithium-ion batteries, which are preferred due to their high power and energy densities.
The performance parameters to be tested mainly include the internal resistance, capacity, open circuit voltage, time dependent self-discharge and temperature rise. The performance of a battery is highly dependent on the weakest cell and the life of the battery will be at par or less than the actual life span of the weakest cell.
Lithium-ion batteries work by collecting current and feeding it into the battery during charging. Normally, a graphite anode attracts lithium ions and holds them as a charge. But interestingly, recent research shows that battery energy density can nearly double when replacing graphite with a thin layer of pure lithium.