Abstract: Disclosed herein is a method of preparing porous graphene from porous graphite, including 1) thermochemically reacting a highly crystalline carbide compound with a halogen element-containing gas to give a porous carbide-derived carbon; 2) treating the carbide-derived carbon with an acid, thus preparing a carbide-derived carbon oxide; and 3) reducing the carbide-derived carbon oxide. An anode mixture for a secondary battery including the graphene and an anode for a secondary battery including the anode mixture are also provided.

Abstract: Disclosed is a method for preparing a carbide-derived carbon-based anode active material. The method includes preparing carbide-derived carbon, and expanding pores of the carbide-derived carbon. Here, expanding of pores is performed as an activation process of heating the prepared carbide-derived carbon in the air. The pores formed inside the carbide-derived carbon can be expanded during the activation process in the preparation of the carbide-derived carbon-based anode active material. In addition, by applying the carbide-derived carbon to an anode active material, lithium secondary battery having improved charge-discharge efficiency can be prepared.

Abstract: The present invention provides a lithium secondary battery, comprising a cathode, an anode, a non-aqueous solution containing a lithium salt and an organic solvent, and a safety vent for removing increased internal pressure, the non-aqueous solution having the prescribed composition and the safety vent having the prescribed operational characteristics. The lithium secondary battery of the present invention can ensure its safety even when overcharged.

Abstract: Disclosed are a non-aqueous electrolyte solution for a lithium secondary battery and a lithium secondary battery comprising the same. The non-aqueous electrolyte solution for a lithium secondary battery may include difluorotoluene having a lowest oxidation potential among components of the non-aqueous electrolyte solution. The lithium secondary battery may have improvement in basic performance including high rate charge/discharge characteristics, cycle life characteristics, and the like, and may remarkably reduce swelling caused by decomposition of an electrolyte solution under high voltage conditions such as overcharge.

Abstract: Disclosed are a non-aqueous electrolyte solution for a lithium secondary battery and a lithium secondary battery comprising the same. The non-aqueous electrolyte solution for a lithium secondary battery may include difluorotoluene having a lowest oxidation potential among components of the non-aqueous electrolyte solution. The lithium secondary battery may have improvement in basic performance including high rate charge/discharge characteristics, cycle life characteristics, and the like, and may remarkably reduce swelling caused by decomposition of an electrolyte solution under high voltage conditions such as overcharge.

Abstract: A solvent-free polymer electrolyte and a secondary battery employing the electrolyte are provided. The electrolyte includes: a porous film, including a first polymer and a second oligomer, the first polymer being at least one selected from the group consisting of poly (vinylidene fluoride-co-hexafluoropropylene) copolymers, polyvinylidenefluorides, polymethylmethacrylates, polyacrylonitriles, polyethyleneoxides, and celluloses having a polyether chain, and the second oligomer being at least one selected from the group consisting of poly(ethylene oxide-co-ethylene carbonate) copolymers with at least one terminal groups substituted by a halogen atom and polyethyleneglycols with at least one terminal group substituted by a halogen atom. An electrolyte comprising the second oligomer and a lithium salt is present in the pores of the porous film.

Abstract: Provided are a solvent-free polymer electrolyte and a secondary battery employing the same. The solvent-free polymer electrolyte includes: a porous film including a first polymer and a second oligomer, the first the group consisting of poly(vinylidene fluoride-co-hexafluoropropylene) copolymers, polyvinylidenefluorides, polymethylmethacrylates, polyacry-lonitriles, polyethyleneoxides, and celluloses having a polyether chain and the second oligomer being at least one selected from the group consisting of poly(ethylene oxide-co-ethylene carbonate) copolymers with at least one terminal groups substituted by a halogen atom and polyethyleneglycols with at least one terminal groups substituted by a halogen atom; and an electrolyte present in the pores of the porous film and including the second oligomer and a lithium salt.