Lithium titanate battery state of health estimation method

Abstract

The system and method for estimating the state of health of a lithium titanate battery provided by the present invention, the method includes: charging / discharging the battery with a constant current, and recording the amount of electricity released by the charge and discharge cycle; calculating the specific heat capacity corresponding to the selected charge and discharge cycle; calculating the specific heat capacity corresponding to the selected charge and discharge cycle; The relationship curve of battery state of health and specific heat capacity and verify the accuracy; estimate the trend of battery state of health. The technical solution provided by this application uses the change of the specific heat capacity of the lithium titanate battery during the decay process to correct it, which not only reflects the influence of traditional aging factors on the battery’s health status, but also adds a specific heat capacity correction factor, so that the new battery The health state prediction model has a more accurate prediction of the health state of the lithium titanate battery, which improves the accuracy of the model.

Description

technical field [0001] The invention relates to the field of health state estimation, in particular to a method for estimating the health state of a lithium titanate battery. Background technique [0002] The intermittent and uncontrollable characteristics of renewable energy such as wind power and solar energy when they are converted into electrical energy will have a serious impact on the security and stability of the grid when they are connected to the grid on a large scale. Therefore, energy storage technology is needed to achieve dynamic supply and demand balance and Provide auxiliary services such as peak shaving and frequency modulation. Among the many existing energy storage technologies, lithium-ion batteries are widely used due to their high energy density, long cycle life, and environmental friendliness. But at the same time, the safety issues of lithium-ion batteries are becoming increasingly prominent. How to accurately estimate the state of health (SOH, State...

AI Technical Summary

Problems solved by technology

[0008] However, the lithium titanate battery is easy to swell during charging and discharging and shelving, especially in a high temperature environment, the main component of the gas generated is H 2 , CO, CO 2 and alkane gases

When the lithium titanate battery is inflated, the volume of the battery increases, and the positive and negative electrodes and the diaphragm are no longer in close contact, which will cause the battery to fail, which will seriously affect the service life of the battery

Flatulence is a unique phenomenon of lithium titanate batteries, but it does not appear in traditional carbon negative batteries. Therefore, the impact of flatulence is not considered in the traditional lithium battery SOH estimation technology. Applying the traditional lithium battery SOH estimation technology to titanium Lithium-acid battery system will produce large errors in estimation

[0009] For this reason, a method for estimating the state of health of a lithium titanate battery is needed, so that it can more accurately predict the SOH of the lithium titanate battery, and overcome the defect that the estimation error of the lithium titanate battery system is relatively large in the prior art

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