Negative electrode plate, preparation method thereof, and secondary battery, battery module, battery pack, and electric apparatus containing same

A preparation method of negative electrode plate, comprising:

• pretreating an emulsion-type binder, wherein a pretreatment method comprises at least one of following operations:
• ultrasonication, settling, centrifugation, and kneading;
• mixing a negative electrode active substance, a conductive agent, and an additive in a predetermined ratio to obtain a first mixture;
• mixing the pretreated emulsion-type binder, the first mixture, and deionized water to obtain a negative electrode slurry;
• and
• applying the negative electrode slurry to at least one surface of a current collector, followed by drying to obtain the negative electrode plate;
• wherein:
• the negative electrode plate comprises a current collector and a negative electrode film layer disposed on the at least one surface of the current collector, wherein the negative electrode film layer comprises a negative electrode active material and the emulsion-type binder, and at least part of the emulsion-type binder is in irregular film-like distribution on a surface of the negative electrode active material;
• and
• the irregular film-like distribution is a state in which, in a scanning electron microscope (SEM) image of the negative electrode film layer taken by a scanning electron microscope at a magnification of 10K, the emulsion-type binder is in irregularly shaped thin film-like distribution on the surface of the negative electrode active material, that is neither in single particle distribution nor in distribution of clusters composed of single particles.

A preparation method of negative electrode plate, comprising:

• mixing a negative electrode active substance, a conductive agent, and an additive in a predetermined ratio to obtain a first mixture;
• mixing an emulsion-type binder, the first mixture, and deionized water uniformly by kneading and stirring to obtain a negative electrode slurry;
• and
• applying the negative electrode slurry to at least one surface of a current collector, followed by drying to obtain the negative electrode plate;
• wherein:
• the negative electrode plate comprises a current collector and a negative electrode film layer disposed on the at least one surface of the current collector, wherein the negative electrode film layer comprises a negative electrode active material and the emulsion-type binder, and at least part of the emulsion-type binder is in irregular film-like distribution on a surface of the negative electrode active material;
• and
• the irregular film-like distribution is a state in which, in a scanning electron microscope (SEM) image of the negative electrode film layer taken by a scanning electron microscope at a magnification of 10K, the emulsion-type binder is in irregularly shaped thin film-like distribution on the surface of the negative electrode active material, that is neither in single particle distribution nor in distribution of clusters composed of single particles.