Electrochemical impedance-based on-line evaluation device for short-circuit state in battery cell

The invention discloses a cell internal short circuit state online evaluation device based on electrochemical impedance, which comprises an acquisition module, a filtering module, a conversion module, a calculation module, an excitation module and an alarm module, and is characterized in that a tested cell, the acquisition module, the filtering module, the conversion module, the calculation module and the alarm module are connected in sequence, and the excitation module is connected with the tested cell. According to the invention, direct current signals of the tested cell are converted into alternating current signals of different frequency bands through circuit modulation, EIS frequency sweep tests of different frequency bands are realized, and then the Weber coefficient of the tested cell is calculated by combining impedance information of a low-frequency region with an equivalent circuit model, so that the purpose of evaluating the short circuit state in the cell on line in real time is achieved. Simplici