A negative electrode includes a current collector and an active substance layer arranged on the current collector, and an ionic conductivity of the active substance layer is 0.01 S/m to 1 S/m. The ionic conductivity of the active substance layer is defined as 0.01 S/m to 1 S/m, so that the electrochemical device can meet requirements for fast charging, and meanwhile, lithium plating on a surface of the negative electrode of the electrochemical device can be inhibited in a fast-charging condition, ensuring safety performance of the electrochemical device.