The invention relates to the technical field of
lithium batteries, in particular to a composite binder
aqueous solution, a
silicon-based negative
pole piece and a preparation method and application of the
silicon-based negative
pole piece. The preparation method of the composite binder
aqueous solution comprises the following steps: dissolving a water-based
polymer binder and a micromolecular physical crosslinking agent in water, adding
pyrrole, stirring, adding an initiator, and mixing to obtain the composite binder
aqueous solution. A
small molecule physical cross-linking agent is introduced into the water-based
polymer binder, and a large number of
hydrogen bond binding sites are increased, so that the
mechanical property of the binder is remarkably enhanced, and the
machinability of the
pole piece is further improved. Meanwhile,
polypyrrole can be generated in the binder through in-situ
polymerization, and the
polypyrrole can be tightly coated on the surfaces of the
silicon particles through
strong interaction between the binder and the silicon particles to form a stable conductive network, so that the charge transfer capability of the
electrode is remarkably improved. In addition, the composite binder is also beneficial to formation of a
solid electrolyte layer rich in Li-N and participates in formation of a
solid electrolyte interface layer, so that the
lithium ion transmission capability of the composite binder is further improved.