Composite negative electrode active material and preparation method therefor, negative electrode plate comprising same, secondary battery, and power consuming device

A composite negative electrode active material comprising a negative electrode active material substrate and a conductive polymer layer on the surface of the negative electrode active material substrate, wherein the cyclic voltammetry curve of the composite negative electrode active material has an oxidation peak within a range of 3.2 V-3.6 V and a reduction peak within a range of 2.1 V-2.6 V, and

• the cyclic voltammetry curve of the composite negative electrode active material is obtained according to the following test method comprising:
• (1) providing a negative electrode plate comprising the composite negative electrode active material;
• (2) using a metal lithium plate as a counter electrode, an electrolyte solution with 1 mol/L of lithium hexafluorophosphate as a solute and a mixed solution of ethylene carbonate and dimethyl carbonate at a volume ratio of 1:1 as a solvent, and a glass fiber as a separator, and assembling same with the negative electrode plate to form a button cell in a glove box filled with argon, and leaving the packaged button cell to stand in the glove box for 12 hours or more for aging same;
• and (3) subjecting the resulting button cell to a cyclic voltammetry test by means of an electrochemical workstation to obtain the cyclic voltammetry curve of the composite negative electrode active material, wherein a scanning voltage is 2.0 V-4.3 V and a scanning rate is 0.1 mV/s,
• wherein the conductive polymer layer comprises a conductive polymer, the conductive polymer includes polyimide,
• wherein the monomer unit of the polyimide is represented by formula 1,
• wherein X represents at least one of the group consisting of the following groups having a ketone carbonyl C═O in the main chain structure thereof:
• an alkyl group, an alicyclic group, an aliphatic heterocyclic group, an aromatic group, and a heteroaromatic group;
• and Y represents one of the following groups:
• wherein #represents the linking position, p at each occurrence independently represents 0, 1, 2, 3 or 4, and Ra at each occurrence independently represents at least one of a halogen atom, C1-C6 alkyl, C1-C6 alkoxy, and C1-C6 haloalkyl.