# US 5,348,726 A · Process for producing manganese dioxide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,348,726 A - Document ID: US5348726A - Status: Granted - Kind: A - Application number: 08/122,966 - Filed: 1993-09-20 - Granted: 1994-09-20 - Earliest claimed: 1992-09-28 - Assignees: Duracell Inc. - Inventors: Enoch I. Wang; Lifun Lin; William L. Bowden - Web page: https://patentgrep.com/patent/US5348726A ## CPC - H01M 4/502: {for non-aqueous cells (H01M4/505 takes precedence)} - C01G 45/024: Manganese dioxide - H01M 4/50: of manganese - C01P 2004/03: obtained by SEM - C01P 2004/10: extending in one dimension, e.g. needle-like - C01P 2006/10: Solid density - C01P 2006/40: Electric properties - C01P 2006/60: Optical properties, e.g. expressed in CIELAB-values - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20) - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract The invention relates to the manufacture of manganese dioxide by a chemical process. The resulting manganese dioxide product takes the form of particles characterized by filament-like protrusions jutting out from its surface. The manganese dioxide particles having such surface features can be manufactured by reacting manganese sulfate with sodium peroxodisulfate in an aqueous solution. The process can be controlled to yield high density manganese dioxide. The manganese dioxide formed in the process can be deposited directly onto the surface of electrolytic manganese dioxide (EMD). The manganese dioxide product the is particularly suitable for use as a cathode active material in electrochemical cells. ## Claims ### Claim 1 A particulate MnO.sub.2 material wherein at least the majority of the particles have filament-like protrusions of gamma MnO.sub.2 radiating outwardly from the surfaces of said particles, and wherein said protrusions are visible at a magnification between about 200 and 2,000 times actual size. ### Claim 2 (depends on 1) The particulate MnO.sub.2 material of claim 1 in which said particles consist essentially of gamma MnO.sub.2. ### Claim 3 (depends on 1) The particulate MnO.sub.2 material of claim 1 in which the interior of said particles comprises a substance other than gamma MnO.sub.2. ### Claim 4 (depends on 1) The particulate MnO.sub.2 material of claim 1 wherein the interior of said particles comprises electrolytic manganese dioxide (EMD). ### Claim 5 (depends on 1) The particulate MnO.sub.2 material of claim 1 wherein the interior of said particles comprises a carbonaceous material selected from the group consisting of graphite and carbon black. ### Claim 6 A hybrid MnO.sub.2 material comprising gamma MnO.sub.2 on the surface of electrolytic manganese dioxide (EMD), wherein the gamma MnO.sub.2 material has filament-like protrusions radiating outwardly from said surface. ### Claim 7 A hybrid MnO.sub.2 material comprising gamma MnO.sub.2 on the surface of a carbonaceous material, wherein the gamma MnO.sub.2 material has a filament-like protrusions radiating outwardly from said surface. ### Claim 8 (depends on 7) The hybrid MnO.sub.2 material of claim 7 wherein the carbonaceous material is selected from the group consisting of graphite and carbon black. ### Claim 9 A hybrid MnO.sub.2 particulate material comprising gamma MnO.sub.2 on the surface of particles, said gamma MnO.sub.2 material having filament-like protrusions radiating outwardly from the surface of said particles, said protrusions being visible at magnification between 200 and 2,000 times actual size. ### Claim 10 A hybrid MnO.sub.2 material comprising gamma MnO.sub.2 on the surface of electrolytic manganese dioxide (EMD), wherein the gamma MnO.sub.2 material has filament-like protrusions radiating outwardly from said surface, said protrusions being visible at a magnification between about 200 and 9,850 times actual size. ### Claim 11 A hybrid MnO.sub.2 particulate material comprising gamma MnO.sub.2 on the surface of particles, said gamma MnO.sub.2 material having filament-like protrusions radiating outwardly from the surface of said particles, said protrusions being visible at magnification between 200 and 9,850 times actual size.