MODIFIED ELECTRODE PLATE, PREPARATION METHOD THEREOF, SECONDARY BATTERY, AND ELECTRIC APPARATUS

A modified electrode plate includes an electrode plate, the electrode plate having element sodium or element lithium on its surface, and the electrode plate including a pre-lithiated negative electrode plate or a pre-sodiated negative electrode plate; a protective film, the protective film including a first group and a hydrophobic group, the first group being attached to the surface of the electrode plate, and the hydrophobic group being distal from the electrode plate and the hydrophobic group including a hydrophobic group and being exposed on a surface of the protective film. Disposing the protective film having the hydrophobic group on the surface of the electrode plate can effectively block water, oxygen, or carbon dioxide in the air so as to effectively prevent water, oxygen, or carbon dioxide from passing through the protective layer to react with active components in the electrode plate.