Enhancing electrical conductivity by defects in metals

High electrical conductivity is crucial for electrics, electronics, communications. Eliminating defects such as grain boundaries and impurities is a primary approach to enhancing electrical conductivity in metals. Although reducing electron-phonon interaction can further contribute to electrical conductivity, only a marginal enhancement is obtained by imposing external pressure even high up to gigapascal. Here we report a contrary strategy to transforming defects into conductive benefits, by forming abundant defects of severely distorted lattice via heterogeneous interface-assisted plastic deformation in metal (copper). Such lattice distortions are generated under a non-extreme condition, and cause internal giant local stress significantly suppressing electron-phonon coupling and thus reducing phonon-caused electron scattering. Consequently, a striking bulk electrical conductivity of > 110% IACS is obtained in the copper at room temperature, which is equivalent to the effect of an external high pressure of about 10 gigapascals. Our work provides an extendable approach for developing high-performance metal conductors.