Abstract: A composite negative electrode, a preparation method therefor, and a battery are provided. The composite negative electrode includes a substrate and a negative electrode coating layer provided on the substrate. The negative electrode coating layer includes a first material and a second material, the first material is a lithium-containing material, and in a direction away from the substrate along the composite negative electrode, the content of the lithium-containing material in at least part of the composite negative electrode gradually increases.

Abstract: A composite negative electrode, a preparation method therefor, and a battery are provided. The method includes: providing a first material on a first substrate to form a first material layer; and providing a second material on a second substrate to form a second material layer, bonding the second material layer to the first material layer, performing hot pressing on the first material layer and the second material layer, and then removing the second substrate to obtain the composite negative electrode, at least part of the composite negative electrode having a concentration gradient in the thickness direction thereof; or directly providing the second material on the first material layer to form a second material layer, and performing hot pressing on the first material layer and the second material layer to obtain a composite negative electrode, some of the composite negative electrode having a concentration gradient in the thickness direction thereof.

Abstract: The disclosure relates to a packaging structure for a power module, a packaging method and an electric vehicle. The packaging structure includes: a circuit board; at least one power chip, where each power chip is fastened on the circuit board, and each power chip is integrated with a sensor that is capable of detecting a working state of the power chip; and a signal chip, where the signal chip is fastened on the circuit board and separated from the power chip, a compiling program is preset in the signal chip, the signal chip is in a communication connection with each sensor, and the signal chip is configured to be capable of being in a communication connection with a predetermined device, so as to output working state data of each power chip to the predetermined device. By detecting the working state of each power chip, the power chip can be protected precisely in real time.