A method for preparing nickel/manganese/lithium/cobalt sulfate and tricobalt tetraoxide from battery wastes adopts the following process: dissolving battery wastes with acid, removing iron and aluminum, removing calcium, magnesium and copper, carrying extraction separation, and carrying out evaporative crystallization to prepare nickel sulfate, manganese sulfate, lithium sulfate, cobalt sulfate or/and tricobalt tetraoxide. By using the method, multiple metal elements, such as nickel, manganese, lithium and cobalt, can be simultaneously recovered from the battery wastes, the recovered products are high in purity and can reach battery grade, battery-grade tricobalt tetraoxide can also be directly produced. The method is simple in process, low in, energy consumption and free in exhaust gas pollution, and can realize zero release of wastewater.

Disclosed is a method of producing high-purity lithium carbonate and barium sulfate from discarded lithium secondary batteries, including: a first process for producing high-purity lithium phosphate from a discarded battery; and a second process for producing lithium sulfate from the lithium phosphate and producing lithium carbonate and barium sulfate from the lithium sulfate. The second process has steps of (a) producing a liquid mixture of lithium phosphate and sulfuric acid, (b) obtaining lithium sulfate by condensing the liquid mixture, (c) dissolving the lithium sulfate in water or a sodium hydroxide aqueous solution, depositing phosphoric acid as lithium phosphate, and performing solid-liquid separation (d) depositing lithium carbonate and performing solid-liquid separation to obtain lithium carbonate, (e) finely grinding the lithium carbonate and classifying the particles, (f) controlling a particle size and shape by dissloving edges of particles or minute particles, (g) performing solid-liquid separation, and (h) depositing barium sulfate.

There are provided methods for preparing lithium hydroxide. For example, such methods can comprise submitting an aqueous composition comprising a lithium compound to an electrolysis under conditions suitable for converting at least a portion of said lithium compound into lithium hydroxide. There are also provided methods for preparing lithium sulphate.

The present invention is to provide a means for efficiently and economically separating and recovering transition metals including nickel and cobalt, and lithium from an aqueous sulfate solution comprising the transition metal and lithium as major components.

The present invention is a process for producing lithium sulfate comprising: a step of concentration-crystallization to an aqueous solution comprising at least lithium sulfate and a transition metal sulfate as main components so as to obtain a slurry comprising lithium sulfate as a solid content, and a step of solid-liquid separation of the slurry obtained in the step of concentration-crystallization so as to separate lithium crystals and a crystallization mother liquor.

The present invention is to provide a means for efficiently and economically separating and recovering transition metals including nickel and cobalt, and lithium from an aqueous sulfate solution comprising the transition metal and lithium as major components.

The present invention is a process for producing lithium sulfate comprising: a step of concentration-crystallization to an aqueous solution comprising at least lithium sulfate and a transition metal sulfate as main components so as to obtain a slurry comprising lithium sulfate as a solid content, and a step of solid-liquid separation of the slurry obtained in the step of concentration-crystallization so as to separate lithium crystals and a crystallization mother liquor.

A process for recovering lithium chloride from a lithium sulfate (Li.sub.2SO.sub.4)-containing mixture is described, comprising a step of sulfate removal using barium chloride (BaCl.sub.2). In embodiments, the process may further comprise one or more steps to reduce the level of one or more metals other than lithium and to reduce the level of sulfate by increasing the pH of the (Li.sub.2SO.sub.4)-containing mixture, e.g., using a calcium salt. In embodiments, treatments to reduce the level of one or more metals other than lithium, sulfate, and other components (e.g., calcium if used) may be used, producing a solution substantially comprising Li.sub.2SO.sub.4 for barium chloride (BaCl.sub.2) treatment, to form a precipitate comprising barium sulfate (BaSO.sub.4) and a solution substantially comprising lithium chloride.

A process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate. So crystallized, the generated metal sulfate may be battery-grade or electroplating-grade.

A device includes an ion-conducting membrane with ion-conducting ceramic particles, and an ion-conducting polymer that surrounds the ion-conducting membrane. The ion-conducting polymer includes a pressure-deformable film with a glass transition temperature lower than an operation temperature of the device.

Embodiments described herein relate to recycling of spent lithium battery material. In some aspects, a method can include suspending a lithium source in a solvent containing an oxidation reagent to extract lithium, forming an extracted lithium solution, separating the extracted lithium solution from residual solids of a lithium source, purifying the extracted lithium solution by precipitating and filtering impurities, and precipitating the lithium in the purified lithium solution to generate lithium carbonate (Li.sub.2CO.sub.3). In some embodiments, the method can further include preprocessing the lithium source to improve kinetics of the lithium extraction. In some embodiments, the preprocessing can include a cutting or shredding step to downsize the lithium source. In some embodiments, the lithium source can include lithium-ion battery waste. In some embodiments, the oxidation reagent can include sodium persulfate (Na.sub.2S.sub.2O.sub.8), potassium persulfate (K.sub.2S.sub.2O.sub.8), ammonium persulfate (NH.sub.4).sub.2S.sub.2O.sub.8, hydrogen peroxide (H.sub.2O.sub.2), ozone (O.sub.3), and/or nitrous oxide (N.sub.2O).

There are provided methods for preparing lithium hydroxide. For example, such methods can comprise submitting an aqueous composition comprising a lithium compound to an electrolysis under conditions suitable for converting at least a portion of said lithium compound into lithium hydroxide. There are also provided methods for preparing lithium sulphate.