State-of-Charge Estimation Techniques for Lithium-Ion Batteries

The lithium-ion battery exhibits favorable characteristics, making it a suitable option for electric vehicles.

Ⅰ. Lithium-Ion Battery: Features

Because of a lithium-ion battery’s high energy density, low self-discharge rate, high voltage, long lifespan, high reliability, and quick recharging capabilities, it has drawn a lot of interest from both the scientific community and the automotive industry.

Compared to the various battery management systems, lithium-ion batteries are predominant in terms of specific energy and specific power. When you look at lithium-ion batteries and other electric vehicle batteries side by side in terms of nominal voltage, life cycle, depth of discharge, and efficiency, lithium-ion batteries seem to be the better choice for electric vehicle use.

Many applications, including those in the military, aerospace industry, electric vehicles, and portable devices, have benefited from the profitable qualities of lithium-ion batteries.

Ⅱ. Challenges

Although lithium-ion batteries have many appealing features, their pressurized, flammable liquid electrolyte can make them dangerous. Even with a comparatively tiny lithium-ion battery package, it can result in explosions and fires under the correct conditions.

For example, thermal runaways caused by overcharging lithium-ion batteries may result in leaks and explosions. However, overdischarging a lithium-ion battery can cause irreversible damage to the battery and hasten its aging process. The state-of-charge of the lithium-ion batteries must always be known in order to guarantee the safe charging and discharging functioning of lithium-ion batteries.

When the lithium-ion batteries are not in a safe operating condition, an accurate state-of-charge prediction allows the cut-off circuitry to disconnect them and initiate battery charging in a safe operating scenario.

The remaining quantity of charge in a battery is indicated by its state of charge, which is an essential parameter of batteries. An accurate state-of-charge calculation prolongs battery life and minimizes catastrophic battery failure.

Furthermore, a reliable and accurate state-of-charge estimate is essential to the effective functioning of electric vehicles. Battery age, ambient temperature, and a host of other variables make state-of-charge determination a challenging and intricate operation.