TITANIUM-NIOBIUM COMPOSITE OXIDE-BASED ELECTRODE ACTIVE MATERIAL AND LITHIUM SECONDARY BATTERY USING THE SAME

• Main Authors: ISHIOKA HIDENORI, NAKAHARA KIYOSHI, SEKI TOSHIMASA, HARADA YASUHIRO, MINO WATARU, INAGAKI HIROKI, TAKAMI NORIO
• Format: Patent
• Language: English; Korean
• Published: 02.09.2015
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

The present invention provides a titanium-niobium composite oxide, as a negative electrode active material for a lithium secondary battery, which shows an excellent cycle capacity retention rate while maintaining the high charge and discharge amount by means of a low-priced solid-phase method. The electrode active material contains, as a main component, a titanium-niobium composite oxide of a monoclinic system, represented as TiNb_xO_(2+5x/2) (X is 1.90 or more and less than 2.00) and contains, as a main component, a carbon coated titanium-niobium composite oxide wherein a crystallite diameter, determined from a half width of X-ray diffraction line of (-110) surface, is 85 nm or more, and a carbon content is 1.0 to 5.0 wt/%, and powder resistivity is 1.0 × 10^4 Ω·cm or less.