A preparation method of phosphotungstic acid includes mixing a mixed solution containing tungsten, phosphorus and an inorganic acid with an organic-alcohol-containing oil phase for extraction, stripping the obtained supported organic phase and distilled water according to an oil phase:aqueous phase volume ratio of 3:1 to 10:1 to obtain a stripping solution; and carrying out thermal evaporation crystallization or spray drying on the stripping solution to obtain a phosphotungstic acid crystal, wherein the organic alcohol is a C7-C20 alcohol. The inventors have found out that the addition of an inorganic acid to a solution of phosphorus or tungsten and the use of an organic alcohol as an extractant can achieve simultaneous and efficient extraction of phosphotungstic acid. It has also been found that the organic-alcohol-containing oil phase has excellent selectivity for phosphotungstic acid molecules in the mixed solution.

A preparation method of phosphotungstic acid includes mixing a mixed solution containing tungsten, phosphorus and an inorganic acid with an organic-alcohol-containing oil phase for extraction, stripping the obtained supported organic phase and distilled water according to an oil phase:aqueous phase volume ratio of 3:1 to 10:1 to obtain a stripping solution; and carrying out thermal evaporation crystallization or spray drying on the stripping solution to obtain a phosphotungstic acid crystal, wherein the organic alcohol is a C7-C20 alcohol. The inventors have found out that the addition of an inorganic acid to a solution of phosphorus or tungsten and the use of an organic alcohol as an extractant can achieve simultaneous and efficient extraction of phosphotungstic acid. It has also been found that the organic-alcohol-containing oil phase has excellent selectivity for phosphotungstic acid molecules in the mixed solution.

The present application relates to expanded graphite and exfoliated graphene oxide. More specifically, the present application relates to process for their preparation and uses thereof. The present application includes a process for preparing expanded graphite comprising: mixing graphite with H2SO4/H3PO4 to form a first mixture; adding KMnO4 to the first mixture to form a second and mixture; adding at least one Fe(III) salt to the second mixture under conditions to form a solid graphite-intercalated compound; separating the solid graphite-intercalated compound from the second mixture; and heating the solid graphite-intercalated compound under conditions to provide the expanded graphite. The present application also includes a process for preparing exfoliated graphene oxide comprising: compressing expanded graphite to form a flexible graphite foil; immersing the flexible graphite foil in a solution comprising at least one alkali metal hydroxide and optionally at least one oxidizing agent, and applying voltage under conditions to electrochemically exfoliate the flexible graphite foil to provide the exfoliated graphene oxide.

A large grain quasi-single-crystal film and a manufacturing method thereof are provided. The metal film having the <111> preferred orientation on its surface is subjected to mechanical tensile force to make the arrangement of crystal grains more ordered. The metal film is grown into a film with large crystal grains having an average diameter of over 500 microns by annealing at a temperature below the recrystallization temperature, thereby obtaining a large grain quasi-single-crystal film having the preferred directions of three axes. The large grain quasi-single-crystal film has a <110> preferred orientation along the tensile direction and a <211> preferred orientation along the direction vertical to the tensile force, and maintains a <111> preferred orientation on its top surface. The present invention can be used to produce highly anisotropic large-area quasi-single-crystal films, and can also be applied to grow 2-dimensional materials or develop anisotropic structures.

A large grain quasi-single-crystal film and a manufacturing method thereof are provided. The metal film having the <111> preferred orientation on its surface is subjected to mechanical tensile force to make the arrangement of crystal grains more ordered. The metal film is grown into a film with large crystal grains having an average diameter of over 500 microns by annealing at a temperature below the recrystallization temperature, thereby obtaining a large grain quasi-single-crystal film having the preferred directions of three axes. The large grain quasi-single-crystal film has a <110> preferred orientation along the tensile direction and a <211> preferred orientation along the direction vertical to the tensile force, and maintains a <111> preferred orientation on its top surface. The present invention can be used to produce highly anisotropic large-area quasi-single-crystal films, and can also be applied to grow 2-dimensional materials or develop anisotropic structures.

Transition metal composite hydroxide particles as a precursor to a cathode active material for use in a non-aqueous electrolyte rechargeable battery, where the transition metal composite hydroxide has secondary particles formed by an aggregation of plate-shaped primary particles and fine primary particles, are described. The secondary particles have a center section formed by the plate-shaped primary particles, a layered structure with a low-density section formed by the fine primary particles, and a high-density section formed by the plate-shaped primary particles on the outside of the center section. The average value of the ratio of the center section outer diameter to the particle size of the secondary particles is 30% to 80%, and the average value of the ratio of the high-density section radial direction thickness to the particle size of the secondary particles is 5% to 25%.

Transition metal composite hydroxide particles as a precursor to a cathode active material for use in a non-aqueous electrolyte rechargeable battery, where the transition metal composite hydroxide has secondary particles formed by an aggregation of plate-shaped primary particles and fine primary particles, are described. The secondary particles have a center section formed by the plate-shaped primary particles, a layered structure with a low-density section formed by the fine primary particles, and a high-density section formed by the plate-shaped primary particles on the outside of the center section. The average value of the ratio of the center section outer diameter to the particle size of the secondary particles is 30% to 80%, and the average value of the ratio of the high-density section radial direction thickness to the particle size of the secondary particles is 5% to 25%.

A method for producing a nickel cobalt complex hydroxide includes first crystallization of supplying a solution containing Ni, Co and Mn, a complex ion forming agent and a basic solution separately and simultaneously to one reaction vessel to obtain nickel cobalt complex hydroxide particles, and a second crystallization of, after the first crystallization, further supplying a solution containing nickel, cobalt, and manganese, a solution of a complex ion forming agent, a basic solution, and a solution containing said element M separately and simultaneously to the reaction vessel to crystallize a complex hydroxide particles containing nickel, cobalt, manganese and said element M on the nickel cobalt complex hydroxide particles crystallizing a complex hydroxide particles comprising Ni, Co, Mn and the element M on the nickel cobalt complex hydroxide particles.

A method for producing a nickel cobalt complex hydroxide includes first crystallization of supplying a solution containing Ni, Co and Mn, a complex ion forming agent and a basic solution separately and simultaneously to one reaction vessel to obtain nickel cobalt complex hydroxide particles, and a second crystallization of, after the first crystallization, further supplying a solution containing nickel, cobalt, and manganese, a solution of a complex ion forming agent, a basic solution, and a solution containing said element M separately and simultaneously to the reaction vessel to crystallize a complex hydroxide particles containing nickel, cobalt, manganese and said element M on the nickel cobalt complex hydroxide particles crystallizing a complex hydroxide particles comprising Ni, Co, Mn and the element M on the nickel cobalt complex hydroxide particles.

The object of the present invention is to provide a method for growing a large-size crystal by laser assisted heating and a dedicated device. The device comprises a laser core heating device, a xenon lamp surface heating device, a base, a vacuum cavity and etc. When a crystal is prepared, seeding and crystal growing are implemented by a xenon lamp-laser synergetic heating mode. According to the present invention, the structure and functions of the dedicated device are designed to introduce, at the center of a float melting zone, a laser heating source having high precision and strong controllability, so that a composite heating mode with xenon lamp surface heating and laser core heating is formed; and combined with the control of process, the method and the device solve the difficulty in growing a large-size test crystal bar and enable the growth of the crystal bar having a diameter up to 35 mm so as to facilitate engineering uses.