A method for recycling lithium-ion batteries, comprising the steps of: a) discharging the lithium-ion batteries; b) chopping the lithium-ion batteries into pieces to provide a mixture of a structural part, a first conductive metal part coated with a cathode layer, and a second conductive metal part coated with an anode layer; c) immersing the pieces of the chopped lithium-ion batteries into a polar solvent to form a heterogeneous mixture; d) processing the heterogeneous mixture with a high shearing mixer for a time period from about 5 minutes to about 5 hours to dissolve a binder material in the cathode and anode layers; e) screening the processed heterogeneous mixture to separate the structural part, first conductive metal part, and second conductive metal part from finer electrode materials comprising cathode and anode materials to provide a suspension comprised of the polar solvent and the finer electrode materials; and f) isolating the finer electrode materials in the suspension from the polar solvent; wherein the polar solvent comprises water; wherein the amount of water in the polar solvent is at least 50%; and wherein the high shearing mixer comprises: (i) a mixing vessel having a upper part and lower conically tapering part; (ii) a screw arranged vertically at the centre of the mixing vessel, wherein the screw comprises a rotary shaft and a rotary blade spirally wound around the rotary shaft; (iii) at least one rotary unit comprising a cylindrical rotary shaft coaxially arranged around the rotary shaft of the screw, a pair of rotary arms horizontally extending radially from the rotary shaft of the rotary unit, a supporting rod vertically extending from each of the rotary arms, and an agitator vane held by each of the supporting rods, wherein each of the agitator vanes comprises an upper portion bent forward relative to the rotation direction of the rotary unit, a middle portion attached to the supporting rod, and an lower portion inclined relative to the radial direction of the rotary unit and extending along the inner wall of the mixing vessel; wherein the screw rotates in a direction to urge the heterogeneous mixture upward and centrifugally, and the rotary unit rotates to urge the heterogeneous mixture downward and centripetally; wherein the cathode material is lithium transition metal oxide selected from the group consisting of LiCoO 2, LiNiO 2, LiNi x Mn y O 2, LiNi x Co y O 2, Li 1+z Ni x Mn y Co 1-x-y O 2, LiNi x Co y Al z O 2, LiV 2 O 5, LiTiS 2, LiMoS 2, LiMnO 2, LiCrO 2, LiMn 2 O 4, LiFeO 2, LiFePO 4, and combinations thereof; wherein each x is independently from 0.3 to 0.8; each y is independently from 0.1 to 0.45; and each z is independently from 0 to 0.2; and wherein the binder material in each of the cathode and anode layers is independently a water-based binder material, or a mixture of water-based and organic-based binder materials. a) discharging the lithium-ion batteries; b) chopping the lithium-ion batteries into pieces to provide a mixture of a structural part, a first conductive metal part coated with a cathode layer, and a second conductive metal part coated with an anode layer; c) immersing the pieces of the chopped lithium-ion batteries into a polar solvent to form a heterogeneous mixture; d) processing the heterogeneous mixture with a high shearing mixer for a time period from about 5 minutes to about 5 hours to dissolve a binder material in the cathode and anode layers; e) screening the processed heterogeneous mixture to separate the structural part, first conductive metal part, and second conductive metal part from finer electrode materials comprising cathode and anode materials to provide a suspension comprised of the polar solvent and the finer electrode materials; and f) isolating the finer electrode materials in the suspension from the polar solvent; (i) a mixing vessel having a upper part and lower conically tapering part; (ii) a screw arranged vertically at the centre of the mixing vessel, wherein the screw comprises a rotary shaft and a rotary blade spirally wound around the rotary shaft; (iii) at least one rotary unit comprising a cylindrical rotary shaft coaxially arranged around the rotary shaft of the screw, a pair of rotary arms horizontally extending radially from the rotary shaft of the rotary unit, a supporting rod vertically extending from each of the rotary arms, and an agitator vane held by each of the supporting rods, wherein each of the agitator vanes comprises an upper portion bent forward relative to the rotation direction of the rotary unit, a middle portion attached to the supporting rod, and an lower portion inclined relative to the radial direction of the rotary unit and extending along the inner wall of the mixing vessel;