Trinary nanogradients at electrode/electrolyte interface for lean zinc metal batteries

•Trinary nanogradients is constructed on the three-dimensional framework.•Bottom-up growth of zinc under gradients of conductivity-dielectric and zincophilicity.•The electrolyte concentration gradient in the surface pore increases the CIP content.•lean-zinc batteries were assembled by reducing the N/P ratio to 2.5.•Oxygen-vacancy in TiO2 promote uniform nucleation of zinc ions.