Lithium battery thermal runaway evaluation method based on multi-parameter fusion

The invention discloses a multi-parameter fusion lithium battery thermal runaway evaluation method, which comprises the following steps of: in an offline stage, acquiring parameters such as voltage, current, pressure and gas concentration in the charging and discharging process of a lithium battery, respectively extracting time domain characteristics, frequency domain characteristics and time-frequency domain characteristics of each parameter, and constructing a multivariate time sequence; selecting a sensitive feature set of each parameter; then designing a depth separable convolution auto-encoder for extracting thermal runaway state features, and training by using a sensitive feature set; in the online stage, the distance between the thermal runaway state characteristic at the current moment and the normal state characteristic at the initial charging and discharging moment of the lithium battery is calculated, and a thermal runaway index TRI is obtained; and evaluating the lithium battery stage according to