The invention relates to a
lithium ion battery negative
pole piece and a preparation method thereof. The
pole piece takes an intermediate
polymer base material as a core, the two sides of the intermediate
polymer base material are coated with conducting
layers with the thickness of 5-20 nm, the conducting
layers are formed by blade
coating,
spin coating or
dip coating of a specific conducting glue solution, and in the formula of the conducting glue solution,
polyvinylpyrrolidone accounts for 10%-30%, carbon nanotubes account for 5%-10%,
metal nanowires account for 1%-5%, ethyl
alcohol accounts for 50%-80%, and
tetraethylammonium tetrafluoroborate accounts for 1%-2%. In addition, a porous material layer is arranged on the outer side of the conducting layer. The preparation method of the negative
pole piece comprises the following steps: pretreating the surface of an intermediate
polymer substrate, preparing a conductive
adhesive solution,
coating two sides of the substrate with the conductive
adhesive solution, and
drying to form a conductive layer; and compounding the porous material layer with the base material with the conductive layer to prepare the integrated
composite electrode plate. According to the novel
current collector structure, traditional
copper foil is replaced by the intermediate polymer base material, the weight is remarkably reduced, the
energy density of the battery is improved, meanwhile, the specific conductive glue solution enables the
microstructure of the conductive layer to be more uniform, the
interface impedance is reduced, the
lithium dendrite growth risk is reduced, and the safety of the battery is greatly improved.