▎ 摘　　要

NOVELTY - Negative electrode sheet comprises negative electrode current collector (1), where upper and lower sides coated with first negative electrode active substance material layer (2), and each layer of first negative electrode active substance material layer coated with second negative electrode active substance material layer (3). The first negative electrode active substance material layer comprises 90-98 wt.% first negative electrode active substance material, 0.5-5 wt.% first conductive agent, 0.5-3 wt.% first thickening agent and 1-5 wt.% first agglomerant. The first and second negative electrode active substance material comprises graphite material, silicon based material or mixture of graphite material and silicon-based material; first and second conductive agent comprising superconducting carbon black super phosphorus (P), carbon nano-tube (CNT) and graphene. USE - Negative electrode sheet for used in lithium-ion battery (claimed). ADVANTAGE - The negative electrode sheet enables to ensure improvement of battery energy density, and optimize battery circulation performance. DETAILED DESCRIPTION - Negative electrode sheet comprises negative electrode current collector (1), where upper and lower sides coated with first negative electrode active substance material layer (2), and each layer of first negative electrode active substance material layer coated with second negative electrode active substance material layer (3). The first negative electrode active substance material layer comprises 90-98 wt.% first negative electrode active substance material, 0.5-5 wt.% first conductive agent, 0.5-3 wt.% first thickening agent and 1-5 wt.% first agglomerant. The first and second negative electrode active substance material comprises graphite material, silicon based material or mixture of graphite material and silicon-based material; first and second conductive agent comprising superconducting carbon black super phosphorus (P), carbon nano-tube (CNT) and graphene; first and second thickening agent comprising sodium carboxymethyl cellulose and lithium carboxymethyl cellulose; first agglomerant comprising styrene butadiene rubber (SBR). The second negative electrode active substance material layer comprises 90-98 wt.% second negative electrode active substance material, 0.5-5 wt.% second conductive agent, 0.5-3 wt.% second thickening agent and 1-5 wt.% second agglomerant. The second agglomerant comprises polyacrylic acid substance (PAA), or mixture of PAA and SBR. An INDEPENDENT CLAIM is included for a preparation method of negative electrode sheet, which involves: (a) stirring negative electrode active substance material, first conductive agent, first thickening agent and first agglomerant according to preset mass ratio, then dissolving in first solvent to disperse to prepare first negative electrode active substance, adjusting solid content of first slurry to 50 ± 5% or adjusting viscosity of first slurry to 3000 ± 1000 centipoise (cp); (b) mixing second negative electrode active substance material, second conductive agent, second thickening agent and second agglomerant, then dissolving in second solvent to disperse to prepare second negative electrode active substance, adjusting solid content and viscosity; (c) coating first negative electrode active material slurry on upper and lower sides of negative electrode current collector, then coating second negative electrode active material slurry with one layer on each layer of first negative electrode active material layer on side away from negative electrode current collector, then drying; (d) rolling negative electrode sheet until compaction density of first and second negative electrode active material layer meets preset pressure; and (e) cutting negative electrode sheet to predetermined size, and obtaining finished product. DESCRIPTION OF DRAWING(S) - The drawing shows a structural schematic view of negative electrode sheet. 1Negative electrode current collector 2First negative electrode active substance material layer 3Second negative electrode active substance material layer