Negative electrode active material and negative electrode using the same and lithium ion secondary battery

• Main Authors: ITO SHUJI, IWAMOTO KAZUYA
• Format: Patent
• Language: English
• Published: 06.12.2011
• Subjects: APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; COMPOUNDS THEREOF; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS; PERFORMING OPERATIONS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY; SPRAYING OR ATOMISING IN GENERAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING

In a negative electrode active material for a lithium ion secondary battery including a silicon oxide capable of absorbing and desorbing lithium ions, a silicon oxide having structural units each in the form of a tetrahedron in which a silicon atom is located at its center and silicon or oxygen atoms are located at its four vertices is used. The structural units are arranged randomly to form an amorphous structure. In the case that the number of oxygen atoms located at the four vertices in the structural units is represented by n (n=0, 1, 2, 3 or 4) and the structural units are represented by Si(n), the number of the structural units NSi(n) in the silicon oxide satisfies the following relations (1) to (3). [ Formula ⁢ ⁢ 1 ] NSi ⁡ ( 0 ) ∑ NSi ⁡ ( n ) ≥ 0.1 ( 1 ) Nsi ⁡ ( 4 ) ∑ NSi ⁡ ( n ) ≤ 0.1 ( 2 ) Nsi ⁡ ( 1 ) + NSi ⁡ ( 2 ) + Nsi ⁡ ( 3 ) ≠ 0 ( 3 )