Simple, material-efficient microgranulation methods are disclosed for aggregating precursor particles into larger product particles with improved properties and, in some instances, novel structures. The product particles are useful in applications requiring uniform, smooth, spherical, or rounded particles such as for electrode materials in lithium batteries and other applications.

The present disclosure is related to a positive electrode active material for lithium secondary batteries, a method for preparing the positive electrode active material, and a lithium secondary battery including the positive electrode active material. The positive electrode active material for lithium secondary batteries includes an overlithiated layered oxide (OLO), and the overlithiated layered oxide includes primary particles having a size in a range of 300 nm to 10 m in an amount ranging from 50 to 100% by volume with respect to the total overlithiated layered oxide.

The present disclosure provides a method for synthesizing pentlandite-type bimetallic (Fe.Math.Co)9S8 compounds. The method includes grinding and mixing sulfur powder with metal salts of Fe and Co to form a homogeneous mixture, and conducting solid-state pyrolysis of the mixture at a temperature of 900 C. in an Argon atmosphere. The synthesized (Fe.Math.Co).sub.9S.sub.8 compound can be used as electrode material in electrochemical processes. In some embodiments, the method further includes dispersing the synthesized (Fe.Math.Co).sub.9S.sub.8 in a Nafion and isopropanol mixture to form a suspension, and coating the suspension on a glassy carbon electrode to form an electrode comprising (Fe.Math.Co).sub.9S.sub.8 pentlandite. The method provides a streamlined approach to synthesizing (Fe.Math.Co).sub.9S.sub.8 pentlandite, a material with potential applications in renewable energy technologies including electrocatalyst for OER in water splitting for hydrogen production.

Improved methods for preparing lithium transition metal oxide particulate such as lithium nickel metal cobalt oxide (NMC) for use in lithium batteries and other applications are disclosed. The lithium transition metal oxide particulate is prepared from appropriate transition metal oxide and Li compound precursors mainly using dry, solid state processes including dry impact milling and heating. Further, novel precursor particulates and novel methods for preparing precursor particles for this and other applications are disclosed.

Improved methods for preparing lithium transition metal oxide particulate such as lithium nickel metal cobalt oxide (NMC) for use in lithium batteries and other applications are disclosed. The lithium transition metal oxide particulate is prepared from appropriate transition metal oxide and Li compound precursors mainly using dry, solid state processes including dry impact milling and heating. Further, novel precursor particulates and novel methods for preparing precursor particles for this and other applications are disclosed.

A lithium transition metal oxide which is capable of minimizing a side reaction with an electrolyte, thereby suppressing the generation of gas during charging and discharging of a lithium secondary battery is provided. The lithium transition metal oxide is a lithium cobalt oxide which contains a hetero-element, wherein the hetero-element includes a 4th period transition metal; and at least one selected from the group consisting of a group 2 element, a group 13 element, a group 14 element, a 5th period transition metal, and a 6th period transition metal. The lithium transition metal oxide has a cumulative 50% particle diameter (D50) of 10.0 m to 25.0 m and a ratio (D.sub.max/D.sub.min) of a maximum particle diameter (D.sub.max) to a minimum particle diameter (D.sub.min) of 10.0 to 60.0 when measured by laser diffraction scattering particle size distribution.

A lithium transition metal oxide which is capable of minimizing a side reaction with an electrolyte, thereby suppressing the generation of gas during charging and discharging of a lithium secondary battery is provided. The lithium transition metal oxide is a lithium cobalt oxide which contains a hetero-element, wherein the hetero-element includes a 4th period transition metal; and at least one selected from the group consisting of a group 2 element, a group 13 element, a group 14 element, a 5th period transition metal, and a 6th period transition metal. The lithium transition metal oxide has a cumulative 50% particle diameter (D50) of 10.0 m to 25.0 m and a ratio (D.sub.max/D.sub.min) of a maximum particle diameter (D.sub.max) to a minimum particle diameter (D.sub.min) of 10.0 to 60.0 when measured by laser diffraction scattering particle size distribution.

Simple, material-efficient microgranulation methods are disclosed for aggregating precursor particles into larger product particles with improved properties and, in some instances, novel structures. The product particles are useful in applications requiring uniform, smooth, spherical, or rounded particles such as for electrode materials in lithium batteries and other applications.

Simple, material-efficient microgranulation methods are disclosed for aggregating precursor particles into larger product particles with improved properties and, in some instances, novel structures. The product particles are useful in applications requiring uniform, smooth, spherical, or rounded particles such as for electrode materials in lithium batteries and other applications.

The present invention relates to a method of preparing a buffer material composed of bentonite modified with a layered double hydroxide (LDH) as a buffer material used for deep geological disposal of radioactive waste, the method including a step (a) of producing a first mixture by adding a compound containing a divalent cationic material, aluminum nitrate (Al(NO.sub.3).sub.3), and bismuth nitrate (Bi(NO.sub.3).sub.3) to a reactor.