Composite lithium supplementing material and preparation method and application thereof

The invention relates to the technical field of secondary batteries, and provides a composite lithium supplementing material and a preparation method and application thereof. The composite lithium supplementing material provided by the invention comprises a substrate, a plurality of carbon fibers and a lithium-rich material, the plurality of carbon fibers are dispersed on the substrate at intervals, and at least part of the lithium-rich material is distributed in the plurality of carbon fibers. According to the composite lithium supplementing material provided by the invention, the carbon fibers are arranged in an interval dispersion manner, so that the toughness, strength and ion and electron migration capability of the carbon fibers are remarkably enhanced, the electric conductivity of the lithium-rich material is effectively improved, the capability of the lithium-rich material for transmitting lithium ions outwards is enhanced, and the lithium supplementing performance of the lithium-rich material is furt