Electronics and Telecommunications Research Institute

Soon Ho Chang

Kwang Sun Ryu

Kwang Man Kim

Young Gi Lee

Yong Joon Park

Xianglan Wu

Nam Gyu Park

Young Sik Hong

Man Gu Kang

Seong-Gu Kang

Xiang Lan Wu

Young-Sik Hong

Provided are a composite polymer electrolyte for a lithium secondary battery in which a composite polymer matrix multi-layer structure composed of a plurality of polymer matrices with different pore sizes is impregnated with an electrolyte solution, and a method of manufacturing the same. Among the polymer matrices, a microporous polymer matrix with a smaller pore size contains a lithium cationic single-ion conducting inorganic filler, thereby enhancing ionic conductivity, the distribution uniformity of the impregnated electrolyte solution, and maintenance characteristics. The microporous polymer matrix containing the lithium cationic single-ion conducting inorganic filler is coated on a surface of a porous polymer matrix to form the composite polymer matrix multi-layer structure, which is then impregnated with the electrolyte solution, to manufacture the composite polymer electrolyte. The composite polymer electrolyte is used in a unit battery. The composite polymer matrix structure can increase mechanical properties. The introduction of the lithium cationic single-ion conducting inorganic filler can provide excellent ionic conductivity and high rate discharge characteristics.

Lithium cationic single-ion conducting filler-containing composite polymer electrolyte for lithium secondary battery and method of manufacturing the same

Provided is a method of producing a nanoparticle-filled phase inversion polymer electrolyte. The method includes mixing a nanoparticle inorganic filler and a polymer with a solvent to obtain a slurry; casting the obtained slurry to form a membrane; obtaining an inorganic nanoparticle-filled porous polymer membrane by developing internal pores in the cast membrane using a phase inversion method; and impregnating the inorganic nanoparticle-filled porous polymer membrane with an electrolytic solution. The polymer electrolyte produced using the method can be used in a small lithium secondary battery having a high capacity, thereby providing an excellent battery property.

Method of producing nanoparticle-filled phase inversion polymer electrolyte

Provided are a composite polymer electrolyte for a lithium secondary battery that includes a composite polymer matrix structure having a single ion conductor-containing polymer matrix to enhance ionic conductivity and a method of manufacturing the same. The composite polymer electrolyte includes a first polymer matrix made of a first porous polymer with a first pore size; a second polymer matrix made of a single ion conductor, an inorganic material, and a second porous polymer with a second pore size smaller than the first pore size. The second polymer matrix is coated on a surface of the first polymer matrix. The composite polymer matrix structure can increase mechanical properties. The single ion conductor-containing porous polymer matrix of a submicro-scale can enhance ionic conductivity and the charge/discharge cycle stability.

Single ion conductor-containing composite polymer electrolyte for lithium secondary battery and method of manufacturing the same

Provided is a cathode composition for lithium secondary battery that includes a lithium-chromium-titanium-manganese oxide that has the formula Li[LiCrTiMn]Owhere 0&#x2266;x&#x2266;0.3, 0&#x2266;y&#x2266;0.3 and 0.1&#x2266;x+y&#x2266;0.3, and layered a-LiFeOstructure. A method of synthesizing the lithium-chromium-titanium manganese oxide includes preparing a first mixed solution by dispersing titanium dioxide (TiO) in a mixed solution of chrome acetate (Cr(OH)(CHCO)) and manganese acetate ((CHCO)Mn.4HO), adding a lithium hydroxide (LiOH) solution to the first mixed solution to obtain homogeneous precipitates, forming precursor powder that has the formula Li[LiCrTiMn]Owhere 0&#x2266;x&#x2266;0.3, 0&#x2266;y&#x2266;0.3 and 0.1&#x2266;x+y&#x2266;0.3 by heating the homogeneous precipitates, and heating the precursor powder to form oxide powder having a layered structure.

Cathode composition for lithium batteries and method of preparing the same

Provided is a lithium-cobalt-manganese oxide having the formula Li[CoLiMn]O(0.05&#x3c;X&#x3c;0.9) which provide a stable structure and a superior discharge capacity, and the method of synthesizing of the same. The method of synthesizing the oxides according to the present invention comprises: preparing an aqueous solution of lithium salt, cobalt salt, and manganese salt; forming a gel by burning the aqueous solution; making oxide powder by burning the gel; forming a fine oxide powder having a layered structure by the twice of treatments. The lithium-cobalt-manganese oxide synthesized according to the present invention has a stable and superior electrochemical characteristic. The oxide is synthesized by simple and low cost heat treatment process.

Li-Co-Mn oxide as cathode material for lithium batteries and method of synthesis of the same

A cathode active material for a lithium secondary cell used in a cellular phone is disclosed. The cathode active material for the lithium secondary cell and the method the same having a high capacity and a long lifetime, different from LiCoOand LiMnO, Li(Ni, Co)O, and V-system oxide that has been researched as the active material for substituting LiCoOare provided. The cathode active material for the lithium secondary cell in the next formula 1 is obtained by heating or chemically treating diadochite [Fe(PO)(SO)(OH).6HO] that is the mineral containing PO, SO, and OH.LiFeM(PO)(SO)(OH)&#x2003;&#x2003;(1) In the formula, M is at least one element selected from a radical consisting of Mg, Ti, Cr, Mn, Co, Ni, Cu, Zn, Al, and Si, with 0&#x2266;a, c&#x2266;0.5, 1&#x2266;b&#x2266;2, 0.5&#x2266;x, y, z&#x2266;1.5.

Cathode active material for lithium secondary cell and method for manufacturing the same

A method of preparing layered lithium-chromium-manganese oxides having the formula Li[CrLiMn]Owhere 0.1&#x2266;X&#x2266;0.5 for lithium batteries. Homogeneous precipitation is prepared by adding lithium hydroxide (LiOH) solution to a mixed solution of chromium acetate (Cr(OH)(CHCO)) and manganese acetate ((CHCO)Mn.4HO), while precursor powders are prepared by firing the precipitation. After that, the precursor powders are subjected to two heat treatment to yield Li[CrLiMn]Owith &#x3b1;-LiFeOstructure.

Method of preparing layered lithium-chromium-manganese oxides for lithium batteries

A method of manufacturing a conducting polymer film including dissolving a lithium salt in an organic solvent; after the lithium salt is completely dissolved in the organic solvent, dissolving a conducting polymer in the organic solvent by adding the conducting polymer little by little in many separate doses into the organic solvent until obtaining a deep blue colored solution; and leaving the deep blue colored solution as it stands over seven days and coating it on a flat surface; and evaporating the solvent from the coated solution. It is possible to work the conducting polymer film in a very thin membrane and to control the thickness as required, since the polymer film can be formed directly from a solution. Furthermore, it is also possible to control the conductivity of the polymer film by varying the type of salts as used and the concentration thereof, and thus its applicability is very diverse as the purpose of using them, for example in electronic/electric components.

Growing community of inventors

Daejeon, South Korea

Soon Ho Chang