A bipolar battery stack

Abstract

The invention provides a bipolar battery stack, in which each electrode plate in the battery stack is provided with an insulating sealing frame around the edge. The insulating sealing frame is provided with a liquid port, an electrolyte outer flow channel, an electrolyte inner flow channel and a hollow inner frame, the electrode material layer is arranged in the hollow inner frame, the liquid port is in fluid communication with the electrolyte outer flow channel and the electrolyte flows out The channel is in fluid communication with the electrolyte inner flow channel. The electrolyte outer flow channel is located between the outer edge of the insulating sealing frame and the outer edge of the battery cell to transport the injected or discharged electrolyte, and the electrolyte inner flow channel is located between the sash edge of the hollow inner sash and the outer edge of the battery cell It is used to infiltrate the electrolyte between the separator layer and the electrode material layer. The electrolyte in the electrolyte outlet channel can be used to make the battery cell in a liquid-rich state, and the longer electrolyte outlet channel prevents the migration of deintercalated ions between adjacent battery cells through the electrolyte outlet channel, thereby preventing Internal short circuit of the battery.

Description

technical field [0001] The invention relates to the field of batteries, in particular to a bipolar battery. Background technique [0002] The battery stack of a bipolar battery consists of two unipolar electrode sheets, several bipolar electrode sheets, a separator, and an electrolyte. A bipolar electrode sheet refers to an electrode sheet with two polarities after coating the positive electrode material layer and the negative electrode material layer on both sides of the bipolar plate. There is a unipolar electrode sheet behind the material layer or the negative electrode material layer. Since the battery cells of a bipolar battery stack are composed of a bipolar plate, a positive electrode material layer, a separator layer, a negative electrode material layer, and another bipolar plate, each battery cell has an independent electrochemical structure, so it can be achieved by increasing the bipolar The number of electrode sheets is used to increase the number of battery ce...

AI Technical Summary

Problems solved by technology

On the one hand, during the long-term use of bipolar batteries, the solid electrolyte film (SEI film) formed on the surface of the electrode active material will continue to thicken, increasing the internal resistance of the battery, reducing the cycle life, and the side reactions generated by the battery will continue to consume Electrolyte, which leads to the reduction of electrolyte in the battery that participates in the electrochemical reaction, thereby affecting the conduction of lithium ions in the battery, reducing battery performance and even causing battery failure

On the other hand, the electrolytes of adjacent battery cells in the bipolar battery stack will form a liquid connection through the liquid port, and the liquid connection will cause ionic current or ion bridge between the battery cells, resulting in a short circuit and a decrease in the overall performance of the battery.

Images