GEM CO., LTD.

The present invention provides a method for recovering valuable metals from waste lithium ion batteries. The method comprises: short-circuit discharging, dismantling, crushing, roasting, and screening on waste lithium ion batteries to obtain active electrode powders; using alkaline solution to wash the active electrode powders, then filtering to remove copper and aluminum; drying the activated electrode powder after alkaline washing treatment, mix the dried activated electrode powder with starch and concentrated sulfuric acid and stir evenly to obtain the mixed material; calcining the mixed material with controlling the atmosphere; taking out the product obtained from calcination and using deionized water to extract the leachate and leaching residue with valence metal ions, and then obtaining the leachate after filtering. The present invention can reduce the concentration of impurity ions in the leaching solution, improve the purity and comprehensive recovery rate of valuable metals, and reduce the recovery cost.

Provided is a compact and lightweight motor complex cooling system with compatibility in which by providing a structure that circulates internal air without introducing air from the outside, an air-cooled radiator used in the conventional air cooling scheme is unnecessary, and only a water-cooled radiator is required, contributing to miniaturization and weight reduction of a device, and the compact and lightweight motor complex cooling system can be installed in an existing motor, and thus has compatibility, and is configured by a combination of air cooling and water cooling using coolant, allowing direct cooling to the end coil windings and the front of shafts of a rotor and a stator and by air cooling, and has excellent cooling efficiency through water cooling.

The invention discloses a ternary positive electrode material coated with nitride/graphitized carbon nanosheets and preparation method thereof. The ternary positive electrode material coated with nitride/graphitized carbon nanosheets includes a ternary positive electrode material matrix and a coating layer; the coating layer is composed of nitride and graphitized carbon; and the graphitized carbon is formed in situ in the coating process of the nitride. Compared with a physical mixing method, the in-situ generated carbon layer is connected to the material matrix more tightly, and the formed conductive network is denser. So that the rate performance of the material is improved to the maximum extent. The preparation method is simple and easy to realize industrial production. And the obtained ternary positive electrode material coated with nitride/graphitized carbon nanosheets has excellent rate performance and cycling stability.

The invention discloses a ternary positive electrode material coated with nitride/graphitized carbon nanosheets and preparation method thereof. The ternary positive electrode material coated with nitride/graphitized carbon nanosheets includes a ternary positive electrode material matrix and a coating layer; the coating layer is composed of nitride and graphitized carbon; and the graphitized carbon is formed in situ in the coating process of the nitride. Compared with a physical mixing method, the in-situ generated carbon layer is connected to the material matrix more tightly, and the formed conductive network is denser. So that the rate performance of the material is improved to the maximum extent. The preparation method is simple and easy to realize industrial production. And the obtained ternary positive electrode material coated with nitride/graphitized carbon nanosheets has excellent rate performance and cycling stability.

The present invention provides a method for recovering valuable metals from waste lithium ion batteries. The method comprises: short-circuit discharging, dismantling, crushing, roasting, and screening on waste lithium ion batteries to obtain active electrode powders; using alkaline solution to wash the active electrode powders, then filtering to remove copper and aluminum; drying the activated electrode powder after alkaline washing treatment, mix the dried activated electrode powder with starch and concentrated sulfuric acid and stir evenly to obtain the mixed material; calcining the mixed material with controlling the atmosphere; taking out the product obtained from calcination and using deionized water to extract the leachate and leaching residue with valence metal ions, and then obtaining the leachate after filtering. The present invention can reduce the concentration of impurity ions in the leaching solution, improve the purity and comprehensive recovery rate of valuable metals, and reduce the recovery cost.

The present invention provides a method of preparing an MOF-coated monocrystal ternary positive electrode material. Firstly, a solution A of nickel, cobalt and manganese metal salts, an ammonia complexing agent solution and a caustic soda liquid are added to a reactor for reaction to obtain a precursor core; then, an organic carboxylate is dissolved in an amount of an organic solvent to obtain a solution B; the solution B and a manganese metal salt solution with a given concentration are added to the reactor and aged to obtain an MOF-coated core-shell structure precursor; the core-shell structure precursor is pre-sintered at a low temperature to obtain a nickel-cobalt-manganese oxide with monocrystal structure; the nickel-cobalt-manganese oxide with monocrystal structure is uniformly mixed with LiOH·H 2 O in a mortar and then calcined at a high temperature to obtain an MOF-coated monocrystal ternary positive electrode material.

Provided are a battery-level Ni—Co—Mn mixed solution and a preparation method for a battery-level Mn solution, the steps thereof comprising: acid dissolution (S 1 ), alkalization to remove impurities (S 2 ), synchronous precipitation of calcium, magnesium, and lithium (S 3 ), deep ageing to remove impurities (S 4 ), synergistic extraction (S 5 ), and refining extraction (S 6 ). The steps of deep ageing to remove impurities (S 4 ) and synergistic extraction (S 5 ) comprise: performing deep ageing on a filtrate obtained from the step of synchronous precipitation of calcium, magnesium, and lithium (S 3 ), and after performing filtration to remove impurities, obtaining an aged filtrate; using P204 to extract the aged filtrate and obtain a loaded organic phase, and subjecting the loaded organic phase to staged back-extraction to obtain the battery-level Ni—Co—Mn mixed solution and a Mn-containing solution. By means of the cooperation between the multiple process steps of synchronous precipitation of calcium, magnesium, and lithium (S 3 ), deep ageing to remove impurities (S 4 ), and synergistic extraction (S 5 ), the impurity content of the obtained battery-level Ni—Co—Mn mixed solution is significantly lowered, and the battery-level Ni—Co—Mn mixed solution can be directly used to prepare a lithium battery ternary precursor material. At the same time, the battery-level Mn solution can also be obtained, which is favorable for large-scale applications of the process and increasing economic benefits.

Provided are a battery-level Ni—Co—Mn mixed solution and a preparation method for a battery-level Mn solution, the steps thereof comprising: acid dissolution (S 1 ), alkalization to remove impurities (S 2 ), synchronous precipitation of calcium, magnesium, and lithium (S 3 ), deep ageing to remove impurities (S 4 ), synergistic extraction (S 5 ), and refining extraction (S 6 ). The steps of deep ageing to remove impurities (S 4 ) and synergistic extraction (S 5 ) comprise: performing deep ageing on a filtrate obtained from the step of synchronous precipitation of calcium, magnesium, and lithium (S 3 ), and after performing filtration to remove impurities, obtaining an aged filtrate; using P204 to extract the aged filtrate and obtain a loaded organic phase, and subjecting the loaded organic phase to staged back-extraction to obtain the battery-level Ni—Co—Mn mixed solution and a Mn-containing solution. By means of the cooperation between the multiple process steps of synchronous precipitation of calcium, magnesium, and lithium (S 3 ), deep ageing to remove impurities (S 4 ), and synergistic extraction (S 5 ), the impurity content of the obtained battery-level Ni—Co—Mn mixed solution is significantly lowered, and the battery-level Ni—Co—Mn mixed solution can be directly used to prepare a lithium battery ternary precursor material. At the same time, the battery-level Mn solution can also be obtained, which is favorable for large-scale applications of the process and increasing economic benefits.

The present invention provides a method of preparing an MOF-coated monocrystal ternary positive electrode material. Firstly, a solution A of nickel, cobalt and manganese metal salts, an ammonia complexing agent solution and a caustic soda liquid are added to a reactor for reaction to obtain a precursor core; then, an organic carboxylate is dissolved in an amount of an organic solvent to obtain a solution B; the solution B and a manganese metal salt solution with a given concentration are added to the reactor and aged to obtain an MOF-coated core-shell structure precursor; the core-shell structure precursor is pre-sintered at a low temperature to obtain a nickel-cobalt-manganese oxide with monocrystal structure; the nickel-cobalt-manganese oxide with monocrystal structure is uniformly mixed with LiOH.H 2 O in a mortar and then calcined at a high temperature to obtain an MOF-coated monocrystal ternary positive electrode material.