Provided is a cellulose derivative composition for a secondary battery binder, a method of preparing a composition for a secondary battery electrode, including the same, and a secondary battery including the same. According to the inventive concept, the cellulose derivative composition for a secondary battery binder may include a compound represented by Formula 1 below.

##STR00001##

A negative electrode for an electrochemical cell of a secondary lithium metal battery is manufactured by a method in which a precursor solution is applied to a major surface of a lithium metal substrate to form a precursor coating thereon. The precursor solution includes an organophosphate, a nonpolar organic solvent, and a lithium-containing inorganic ionic compound dissolved therein. At least a portion of the nonpolar organic solvent is removed from the precursor coating to form a protective interfacial layer on the major surface of the lithium metal substrate. The protective interfacial layer exhibits a composite structure including a carbon-based matrix component and a lithium-containing dispersed component. The lithium-containing dispersed component is embedded in the carbon-based matrix component and includes a plurality of lithium-containing inorganic ionic compounds, e.g., lithium phosphate (Li.sub.3PO.sub.4) and lithium nitrate (LiNO.sub.3).

The present invention provides a nanoporous carbon composite (NCC) for use as an electrode material. NCC comprises active electrode material, one or more additives in a form of particles or fibers, and a nanoporous carbon phase that binds pieces of the active electrode material and pieces of the additive with each other. The nanoporous carbon phase is derived from a polyimide precipitate prepared from imidization of a poly(amic acid) solution. NCC further comprises micro-cracks distributed throughout the NCC to build a three-dimensional (3D) network, wherein the micro-crack is bounded in one or more parts by a surface of the active electrode material or the additive.

A positive electrode active material includes a plurality of groups of particles. The plurality of groups of particles has a particle diameter of more than or equal to 300 nm and less than or equal to 3 μm. Each of the groups includes two or more particles. The two or more particles are each a lithium-containing complex phosphate including one or more of iron, nickel, manganese, and cobalt. The group of particles includes a first particle and a second particle each having a major diameter and a minor diameter in the upper surface when seen from a predetermined direction. The major diameters of the first and second particles are substantially parallel to each other. The major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm.

A positive electrode active material includes a plurality of groups of particles. The plurality of groups of particles has a particle diameter of more than or equal to 300 nm and less than or equal to 3 μm. Each of the groups includes two or more particles. The two or more particles are each a lithium-containing complex phosphate including one or more of iron, nickel, manganese, and cobalt. The group of particles includes a first particle and a second particle each having a major diameter and a minor diameter in the upper surface when seen from a predetermined direction. The major diameters of the first and second particles are substantially parallel to each other. The major diameter of the first particle is two to six times larger than the minor diameter of the first particle and the minor diameter of the first particle is more than or equal to 20 nm and less than or equal to 130 nm.

A co-fired all-solid-state battery that includes a negative electrode, a solid electrolyte layer, and a positive electrode. The negative electrode contains a negative electrode active material and a garnet-type solid electrolyte. The negative electrode active material contains Li, V, and O. The negative electrode active material has a mole ratio (Li/V) of a Li content to a V content of 2.0 or more. The garnet-type solid electrolyte contains Li, La, Zr, and O.

The invention relates to a process for the preparation of carbon-deposited alkali metal oxyanion and the use thereof as cathode material in lithium secondary batteries wherein the process comprises synthesis of partially reacted alkali metal oxyanion, a wet-based nanomilling step, a drying step and a subsequent carbon deposition step performed by a thermal CVD process. The invention also relates to carbon deposited alkali metal oxyanion with less than 80 ppm of sulfur impurities for the preparation of a cathode of lithium secondary batteries with exceptional high-temperature electrochemical properties.

A lithium borosilicate composition, consisting essentially of a system of lithium oxide in combination with silicon oxide and boron oxide, wherein said lithium borosilicate comprises between 70-83 atomic % lithium based on the combined atomic percentages of lithium, boron and silicon, and wherein said lithium borosilicate is a glass, is disclosed.

The present invention relates to a lithium secondary battery, comprising: a negative electrode comprising a negative electrode active material layer comprising a soft carbon negative electrode active material and a byproduct having an average particle size (D50) of 10 to 70 nm; a positive electrode comprising a positive electrode active material; and an electrolyte.

The present invention relates to a lithium secondary battery, comprising: a negative electrode comprising a negative electrode active material layer comprising a soft carbon negative electrode active material and a byproduct having an average particle size (D50) of 10 to 70 nm; a positive electrode comprising a positive electrode active material; and an electrolyte.