▎ 摘　　要

NOVELTY - Preparing lithium composite sheet comprises e.g. (1) dispersing graphene oxide in dimethylformamide, carrying ultrasonic treatment to obtain graphene dispersion; heating graphene dispersion in oil bath, adding hexamethylene diisocyanate, and maintaining temperature; (2) adding sodium lignosulfonate to dimethylformamide, heating to completely dissolve sodium lignosulfonate to obtain sodium lignosulfonate solution; adding sodium lignosulfonate solution to the mixture obtained in the step (1) to obtain mixed solution-A, protecting mixed solution-A, heating and reacting; and (3) naturally cooling. USE - The lithium composite sheet useful in high performance lithium battery (claimed). ADVANTAGE - The lithium composite sheet: avoids the formation of lithium dendrite, and improves the safety of the battery. DETAILED DESCRIPTION - Preparing lithium composite sheet comprises (1) dispersing graphene oxide in dimethylformamide, carrying ultrasonic treatment to obtain 1-2 mg/ml graphene dispersion; heating graphene dispersion in oil bath to 100-140 degrees C, adding hexamethylene diisocyanate at rate of 50-100 mu l/minutes, and maintaining temperature for 30-60 minutes; (2) adding sodium lignosulfonate to dimethylformamide, heating to 80 degrees C to completely dissolve the sodium lignosulfonate to obtain 0.6-1 mg/ml sodium lignosulfonate solution; adding sodium lignosulfonate solution to the mixture obtained in the step (1) at rate of 10-20 ml/minutes, to obtain mixed solution-A, protecting mixed solution-A under inert gas, heating to 100-140 degrees C, and reacting for 60-120 minutes; where the concentration of graphene oxide reduced in the mixed solution-A is 0.25-0.5 mg/ml and concentration of sodium lignosulfonate is 0.5-0.7 mg/ml; (3) naturally cooling the reaction solution to room temperature, taking out, washing with deionized water by centrifugation, freezing and drying for 12-24 hours to obtain reduced graphene oxide coated sodium lignosulfonate (rGO.SL) composite material; (4) mixing the reduced graphene oxide coated sodium lignosulfonate composite material and adhesive in mass ratio of 7:3, adding N-methylpyrrolidone to prepare a slurry of reduced graphene oxide coated sodium lignosulfonate (rGO.SL) composite material at concentration of 0.4-0.5 mg/ml, grinding in glove box until the slurry is deep black paste, uniformly coating on the surface of the lithium plate at coating thickness of 30-50 mu m, and baking.