State of charge lithium ion battery

Are lithium-ion batteries effective state of charge estimation?

Implementing carbon neutrality and emission peak policies requires a high-level electric vehicle field. Lithium-ion batteries have been considered an essential component of electric vehicle power batteries. Effective state of charge (SOC) estimation for lithium-ion batteries is a critical problem that needs to be addressed at present.

What is the state of charge of a battery?

When it comes to batteries, understanding the state of charge (SoC) is crucial. SoC is the level of charge of a battery relative to its capacity and is usually expressed as a percentage. For example, a battery that is 50% charged has an SoC of 50%. There are several methods to measure SoC, including voltage-based methods and coulomb counting.

What is a lithium ion battery energy storage system?

As a critical link in the new energy industry chain, lithium-ion (Li-ion) battery energy storage system plays an irreplaceable role. Accurate estimation of Li-ion battery states, especially state of charge (SOC) and state of health (SOH), is the core to realize the safe and efficient utilization of energy storage systems.

What are lithium ion batteries?

Lithium-ion batteries have made a breakthrough in the transportation industry, allowing for vehicles to be tailpipe emission-free. Lithium-ion batteries have relatively high specific energy, long life cycle, and low self-discharge. As a result, they are much more suitable for different applications.

How to charge a lithium ion battery?

Initially, the battery was charged using CC method with 1.6 A (0.5 C) current until the charge voltage reached 4.2 V. Then, the battery was charged using CV method with 4.2 V until the charge current dropped to 0.064 A (0.02 C).

How accurate is SoC estimation of lithium-ion batteries?

SOC estimation of lithium-ion batteries is compulsory for the safe and efficient operation of EVs. An accurate SOC estimation method improves the battery lifespan by controlling overcharge and overdischarge states 6. However, accuracy of SOC is influenced by electrochemical reactions, material degradation, and aging cycles.