A two-stage method of producing purified graphite is described. The first stage of the method comprises the steps of subjecting graphite material to a caustic bake and releasing any remaining caustic using water. The graphite material is then subjected to a first acid wash. Neutralising and washing the acid washed graphite material is then performed to deliver an intermediate purified graphite product. In the second stage the intermediate purified graphite product is subjected to a low temperature caustic leach. Any remaining caustic in the intermediate purified graphite product is released using water, and the intermediate purified graphite product is subjected to a second acid wash. Finally, neutralising and washing the intermediate purified graphite product is performed to deliver a final purified graphite product with a purity of 99.95% C and above.

A two-stage method of producing purified graphite is described. The first stage of the method comprises the steps of subjecting graphite material to a caustic bake and releasing any remaining caustic using water. The graphite material is then subjected to a first acid wash. Neutralising and washing the acid washed graphite material is then performed to deliver an intermediate purified graphite product. In the second stage the intermediate purified graphite product is subjected to a low temperature caustic leach. Any remaining caustic in the intermediate purified graphite product is released using water, and the intermediate purified graphite product is subjected to a second acid wash. Finally, neutralising and washing the intermediate purified graphite product is performed to deliver a final purified graphite product with a purity of 99.95% C and above.

A method for selectively separating a carbon-containing material from a mixture comprising a positive electrode and a negative electrode originating from electrochemical cells and/or accumulators, the method comprising the following successive steps: a) providing a mixture comprising a positive electrode and a negative electrode, each electrode comprising a current collector, an active material and a binder, the active material of the negative electrode being a carbon-containing material, preferably graphite, b) contacting the mixture comprising the positive electrode and the negative electrode with a separation solution, in the presence of ultrasound, the separation solution comprising a solvent and, optionally, additives, until selectively separating the carbon-containing material from the current collector of the negative electrode, the active material of the positive electrode remaining secured to the current collector of the positive electrode.

A method for selectively separating a carbon-containing material from a mixture comprising a positive electrode and a negative electrode originating from electrochemical cells and/or accumulators, the method comprising the following successive steps: a) providing a mixture comprising a positive electrode and a negative electrode, each electrode comprising a current collector, an active material and a binder, the active material of the negative electrode being a carbon-containing material, preferably graphite, b) contacting the mixture comprising the positive electrode and the negative electrode with a separation solution, in the presence of ultrasound, the separation solution comprising a solvent and, optionally, additives, until selectively separating the carbon-containing material from the current collector of the negative electrode, the active material of the positive electrode remaining secured to the current collector of the positive electrode.

An efficient and green method for selective extraction of Li from end-of-life secondary LIBs of any capacity and size is provided. Electrochemical driven selective lithium deposition is targeted at the anode/separator interface of the end-of-life LIB. The deposited Li is recovered by processing of an opened or dismantled battery using only distilled or de-ionized water. The process not only enables the recovery of the plated lithium at the anode/separator interface, but also extracts the lithium from the organic salts and/or inorganic salts in the solid electrolyte interface (SEI) layers and from the electrolyte in the separator. In addition, the method partially strips the cyclable Li from the cathode and concentrates it at the anode/separator interface. The concentrated Li is extracted by using aqueous solution such as distilled or de-ionized water followed by recovery of the Li from aqueous solution. After Li recovery from the anode, the method can also enable the recovery of battery-grade graphite.

An efficient and green method for selective extraction of Li from end-of-life secondary LIBs of any capacity and size is provided. Electrochemical driven selective lithium deposition is targeted at the anode/separator interface of the end-of-life LIB. The deposited Li is recovered by processing of an opened or dismantled battery using only distilled or de-ionized water. The process not only enables the recovery of the plated lithium at the anode/separator interface, but also extracts the lithium from the organic salts and/or inorganic salts in the solid electrolyte interface (SEI) layers and from the electrolyte in the separator. In addition, the method partially strips the cyclable Li from the cathode and concentrates it at the anode/separator interface. The concentrated Li is extracted by using aqueous solution such as distilled or de-ionized water followed by recovery of the Li from aqueous solution. After Li recovery from the anode, the method can also enable the recovery of battery-grade graphite.

A method for recycling spent carbon cathode of aluminum electrolysis includes the following steps: (1) crushing and sieving spent carbon cathode, to obtain carbon particles; (2) mixing the carbon particles with a sulfuric acid solution, to obtain a slurry A, and then performing pressure leaching, to obtain a slurry B; (3) evaporating and concentrating the slurry B until a mass percentage of water is lower than 8%, to obtain a slurry C; (4) adding concentrated sulfuric acid to the slurry C to obtain a slurry D, then roasting the slurry D at 150-300° C. for 0.5-10 h, and then roasting at 300-600° C. for 0.5-8 h, to obtain the roasted carbon; and calcining the roasted carbon at a high temperature, to obtain the purified carbon, or mixing the roasted carbon with a leaching agent, and performing leaching, filtering, and washing, to obtain the purified carbon.

A method for preparing artificial graphite, including the steps of: pulverizing a carbonaceous material; carrying out a first deferrization to remove magnetic foreign materials generated by pulverizing the carbonaceous material to form a first deferrization product; granulating the first deferrization product of the first deferrization step to form a granulated product; graphitizing the granulated product to form a graphitized product; and carrying out a second deferrization on the graphitized product to remove magnetic foreign materials from the graphitized product to form the artificial graphite. A negative electrode including the artificial graphite and a lithium secondary battery including the negative electrode are also disclosed.

The present invention relates to a composition for the production of a graphite powder, suitable for making high performance lithium-ion battery anodes and other applications. The composition of matter comprises a biochar, a metal and graphite. The biochar is typically derived from the pyrolysis of woody biomass. The metal is typically a transition metal derived from the decomposition and reduction of an organic or inorganic metallic compound. The graphite is highly crystalline and has a wide range of morphologies or structures.

The present invention relates to a composition for the production of a graphite powder, suitable for making high performance lithium-ion battery anodes and other applications. The composition of matter comprises a biochar, a metal and graphite. The biochar is typically derived from the pyrolysis of woody biomass. The metal is typically a transition metal derived from the decomposition and reduction of an organic or inorganic metallic compound. The graphite is highly crystalline and has a wide range of morphologies or structures.