The invention discloses a
lithium ion battery internal
short circuit fault detection method based on time-frequency fusion, and the method comprises the steps: firstly constructing a fractional order
equivalent circuit model fused with an electrochemical aging mechanism, and simulating the paths of
conductivity reduction, active material loss and
lithium inventory reduction in combination with an aging
empirical formula; joint modeling of the aging process and the random internal
short circuit is achieved, and multi-cycle
voltage and current and electrochemical impedance
spectroscopy data are obtained; secondly, extracting
time domain features by using a
time domain attention enhanced long-short-
term memory network, and analyzing
frequency domain information by using a multi-scale frequency sensing
convolutional neural network; and then weighting and screening two types of
modal features through a dynamic gating fusion module, introducing a cross attention mechanism to establish dependency mapping between time-
frequency domain features, and finally outputting an internal
short circuit fault detection result. The method can solve the problems that in the
lithium ion battery aging process, due to
lithium dendrite growth, the internal short circuit early fault is high in concealment, and single time-frequency characteristics are difficult to detect, and early high-precision recognition of the internal
short circuit fault can be achieved.