The difficulties and significance of research on health status of lithium battery

Research on the health and life of Lithium Batteries is receiving more and more attention, but the SOH research of batteries is still in the primary stage, which is important for the following three reasons.

1. Long research period and strict control of experimental conditions

Lithium Iron Phosphate Battery life cycle is long, battery ageing experiment cycle is very long, in the test process, the temperature, charge and discharge current and charge and discharge cut-off voltage should be strictly controlled, and every once in a while to evaluate the ageing of the battery.

2, the battery internal status monitoring and analysis is difficult

The SOH research of lithium-ion batteries involves the internal state variables of the battery, such as internal temperature, electrolyte concentration and internal resistance in the electrochemical model, and it is very difficult to accurately monitor the internal state of the battery, but also to perform quantitative analysis of these state variables, which makes the SOH research of the battery difficult to solve.

3. Coupling of different factors

Battery operating temperature, charge and discharge rate, and discharge depth are all factors that affect battery ageing and life, and these factors are common, and the research of battery SOH requires the decoupling of various influencing factors. However, these factors are interrelated, the decoupling conditions are difficult to control, and it is difficult to perform decoupling analysis at present.

Research significance of Li-ion battery SOH

Battery SOH research is difficult and progress is slow, but SOH research has high value for battery use, maintenance and evaluation, and can provide the basis and reference for planning, policy and industrial development, and has important significance.

1, the importance of battery management

The battery management system estimates the battery charge status and the remaining battery capacity. If the battery management system can grasp the ageing rule and the health status of the battery, it can manage the battery throughout the battery life cycle.

2, the importance of battery usage and maintenance

SOH research is helpful to understand the factors affecting battery aging and to provide theoretical guidance for battery use and maintenance. For the use and maintenance of the battery, understanding the factors that affect the aging of the battery can reduce the high and low temperature and overcharge and overdischarge and other harmful conditions of battery use; knowing the current health status of the battery can help judge the inherent hidden dangers and life of the battery, and provide a reference for battery maintenance and replacement.

3, the importance of lithium batteries economic evaluation

The accurate evaluation of SOH is of great importance for the economic evaluation of batteries. Different application scenarios, usage modes and maintenance methods of lithium-ion batteries cause the difference in battery life, so the economic evaluation of battery usage costs and economic benefits are different. Through SOH research, the ageing model of the battery will be established to support the analysis of the economic supply data of the battery, which will provide effective support for the company's investment decision, government policy formulation and industrial development planning.