Abstract: Disclosed is a nonaqueous electrolyte for a lithium-ion secondary battery that contains an addictive for preventing destruction of a solid electrolyte interface (SEI) layer and hence decomposition of the electrolyte that may cause generation of a gas, thereby preventing swelling of the battery caused by the gas generated from the inside of the battery at a high temperature. More specifically, the present invention provides an electrolyte that includes, as an additive, 2-sulfobenzoic acid cyclic anhydride represented by the formula 1: The electrolyte contains the additive in an amount of 0.1 to 10.0 wt. %.

Abstract: A method for searching for a frequency burst (FB) by a mobile station (MS) in a mobile communication system that acquires synchronization between a base station (BS) and the MS using a frame including the FB and a synch burst (SB). In the FB search method, the MS receives a signal on the frame, performs thereon filtering for extraction of the FB in units of 1 block with a first size, and determines whether a ratio of filter input energy to filter output energy is greater than or equal to a threshold. If the ratio of filter input energy to filter output energy is greater than or equal to the threshold, the MS calculates an energy ratio by collecting, in units of a window with a predetermined size, a ratio of the filter input energy to the filter output energy, calculated in units of a block with a second size being less than the first size. The MS determines, as a position of the FB, a position of a window of an energy ratio having a peak value among energy ratios calculated in units of the window.

Abstract: Disclosed is a nonaqueous electrolyte for a lithium-ion secondary battery that contains an addictive for preventing destruction of a solid electrolyte interface (SEI) layer and hence decomposition of the electrolyte that may cause generation of a gas, thereby preventing swelling of the battery caused by the gas generated from the inside of the battery at a high temperature. More specifically, the present invention provides an electrolyte that includes, as an additive, 2-sulfobenzoic acid cyclic anhydride represented by the formula 1: The electrolyte contains the additive in an amount of 0.1 to 10.0 wt. %.

Abstract: Disclosed is a positive active material for a rechargeable lithium battery. The active material includes a cobalt-based compound selected from the group consisting of the compounds represented by the formulas 1 to 4. The active material has a structure of secondary particles with a size of 10 to 30 &mgr;m and the secondary particle is gathered with primary particles with a size of 1 to 5 &mgr;m. The active material includes a metallic oxide coated on the cobalt-based compound. LiCoA2  (1) LiCoO2-xBx  (2) LiCo1-xMxA2  (3) LiCo1-xMxO2-yBy  (4) where A is selected from the group consisting of O, S, F and P, B is selected from the group consisting of S, F and P, M is a transition metal selected from Al, Mg, Cr or Mn; Sr; or lanthanide metal selected from La or Ce; 0<x<1 and 0<y<1.