Self-discharging detection system for lithium ion battery

Abstract

The invention discloses a self-discharging detection system for a lithium ion battery. The system includes a tomography measurement system, a data collecting system, an electrochemical characteristic measuring system and a detection control system. The tomography measurement system is used for obtaining complete data required for reconstructing a three-dimensional tomography image of the lithium ion battery; the data collecting system is used for performing treatment such as amplification, A / D conversion and the like on output signals of the tomography measurement system. The electrochemical characteristic measuring system is used for acquiring basic parameters such as voltage, current, capacity and the like of the lithium ion battery. The detection control system is used for scanning control during the data collection process, obtaining the self-discharging rate of the lithium ion battery and performing treatment such as display, storage and the like. The system provided by the invention realizes real time, lossless and accurate detection of the self-discharging rate of the lithium ion battery and is used for self-discharging rate detection during the lithium ion battery production process and lithium ion battery automatic sorting based on the self-discharging rate, and has important realistic meaning in improving the technique level in battery self-discharging detection of China.

Description

technical field [0001] The invention relates to the technical field of battery self-discharge detection, in particular to a lithium-ion battery self-discharge detection system. Background technique [0002] With the intensification of the global energy shortage, the new energy industry has quietly emerged, and the secondary battery technology with good application prospects has been scrambled for research. Lithium-ion batteries are widely used in various instruments and electric vehicles as energy systems due to their non-polluting, high specific energy, and long cycle life. The self-discharge phenomenon of lithium-ion batteries not only causes the loss of energy of the battery itself, but also reduces the life of the lithium battery pack due to the inconsistency of self-discharge among the batteries, and the capacity decays rapidly, causing the battery management system (BMS) to charge the battery. There is a large error in the prediction of the state of state (SOC), and t...

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Problems solved by technology

However, the existing definition method of direct measurement of capacity loss at home and abroad, open circuit voltage decay rate measurement method and capacity maintenance method only use the physical characteristics of the battery, such as battery capacity, charge and discharge voltage and current, and internal resistance, as the self-discharge rate. The only measurement parameter, but ignores the real-time measurement and analysis of its structure and shape, which increases the randomness of the measurement data, which leads to the problems of long measurement period and poor data reliability in these methods

[0005] Although some scholars at home and abroad use methods such as electron microscopy, surface analysis, X-ray diffraction, infrared spectroscopy, and small-angle laser scattering to analyze the microscopic morphology and structure of self-discharged battery materials, but they have the ability to break samples. Due to the lack of circularity, narrow observation range, poor representation and two-dimensionality, it is difficult to completely and quantitatively show the relationship between the multi-dimensional shape change of the internal structure of the battery material and its self-discharge during the production process, which greatly hinders the self-discharge measurement of the battery. Technological development and improvement of power battery technology level

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