Auxiliary device and method for improving stability and safety of lithium metal battery based on external ultrasonic field

Abstract

The invention discloses an auxiliary device for improving the stability and the safety of a lithium metal battery based on an external ultrasonic field. The device comprises a battery charging box, abattery charging and discharging management system, a controller, an ultrasonic excitation signal transmitter and an ultrasonic transduction device. The battery charging box is of a closed box body structure. The battery charging box is filled with cooling liquid and is provided with a notch groove for accommodating a lithium metal battery; the battery charging and discharging management system isused for being connected with the lithium metal battery in the notch groove; the controller is connected with the ultrasonic transduction device through the ultrasonic excitation signal emitter, andthe ultrasonic transduction device is used for applying ultrasonic longitudinal waves to a plurality of outer surfaces of the lithium metal battery when the lithium metal battery is charged. The diffusion rate of the lithium ions in the electrolyte is improved by using an ultrasonic means, so that the purpose of assisting in improving the stability and safety of the lithium metal battery is achieved. Different from the current traditional improvement strategy, the device is simple in working mode, low in cost, high in practicability and obvious in improvement effect.

Description

technical field [0001] The invention belongs to the technical field of chemical power sources, and more specifically relates to an auxiliary device and method for the stability and safety of lithium metal batteries. Background technique [0002] Lithium-ion secondary batteries are also known as "rocking chair batteries". Their main working principle is to use lithium ions to intercalate and extract back and forth between the positive and negative electrode materials of the battery to achieve repeatable charge and discharge applications. As an advanced electrochemical energy storage technology, lithium-ion batteries have been widely used in energy storage power stations, 3C electronics, electric vehicles and other fields. However, the performance of current lithium-ion batteries, especially the energy density, cannot fully meet the needs of practical applications. Unfortunately, the energy density of current commercial batteries is close to its theoretical specific capacity,...

AI Technical Summary

Problems solved by technology

However, the large-scale production and long-term effectiveness of such strategies need to be improved

[0005] To sum up, the cycle stability and safety of lithium metal batteries mainly depend on the uniformity of deposition and dissolution of lithium ions on the surface of lithium metal negative electrodes. When the concentration gradient of lithium ions in the electrolyte becomes larger, uneven lithium metal negative electrode surface occurs The deposition and dissolution of lithium ions will lead to the growth of lithium dendrites, resulting in a decrease in the coulombic efficiency of the battery, capacity attenuation, and even the risk of lithium dendrites piercing the separator, causing thermal runaway or even fire and explosion of the battery

The traditional method of suppressing lithium dendrites and improving the stability and safety of lithium metal batteries has the disadvantages of complex process, high cost, and difficulty in large-scale production.

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