▎ 摘　　要

NOVELTY - Secondary ion battery capacity compensation functional diaphragm comprises coating coated on the surface of the diaphragm substrate. The coating comprises phosphorus-based composite, conductive material and agglomerant. The mass ratio of the phosphorus-based composite to the conductive material to the binder is 5-15:1:1. The phosphorus-based composite is LixPy and/or NamPn, where x is 0-3, y is 0-11, m is 0-3 and n is 0-11. USE - The diaphragm is useful for preparing secondary alkali metal ion battery (claimed), energy storage and energy supply device. ADVANTAGE - The diaphragm improves secondary ion battery head cycle coulomb efficiency, reduces irreversible capacity loss of the battery, and improves the energy density and long cycle life. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: preparing the secondary ion battery capacity compensation functional diaphragm; use method of the diaphragm, comprising preparing secondary alkali metal ion battery, and assembling the battery with the coated side of the diaphragm facing the anode side; and econdary ion battery.