Abstract: To provide a negative electrode material capable of giving a lithium ion secondary battery that is sufficiently small in the charge/discharge irreversible capacity observed at the initial cycle stage, has excellent high-temperature storage characteristics, and reduced in the gas generation at the initial cycle stage as well as during high-temperature storage. A carbon material for lithium ion secondary battery, wherein the surface functional group amount O/C value represented by the following formula 1 is from 1 to 4% and the sum (Cl/C+S165/C) of the surface functional group amount Cl/C value represented by the following formula 2 and the surface functional group amount S165/C value represented by the following formula 3 is from 0.05 to 0.

Abstract: To provide a negative electrode material capable of giving a lithium ion secondary battery that is sufficiently small in the charge/discharge irreversible capacity observed at the initial cycle stage, has excellent high-temperature storage characteristics, and reduced in the gas generation at the initial cycle stage as well as during high-temperature storage. A carbon material for lithium ion secondary battery, wherein the surface functional group amount O/C value represented by the following formula 1 is from 1 to 4% and the sum (Cl/C+S165/C) of the surface functional group amount Cl/C value represented by the following formula 2 and the surface functional group amount S165/C value represented by the following formula 3 is from 0.05 to 0.

Abstract: [Object] An object of the present invention is to provide a water treatment system capable of increasing the treatment rate by causing active species, such as radicals, produced by discharge to efficiently act on treatment water. [Solution] The water treatment system is characterized by including: at least a pair of cylindrical electrode 3 and a linear electrode 4 in a treatment chamber 2, the linear electrode 4 being disposed along the central axis of the cylindrical electrode 3; and treatment water mist supply means 7 for supplying treatment water in the form of mist composed of droplets having a particle diameter of 1500 ?m or less to a discharge space generated by applying a high voltage between the cylindrical electrode 3 and the linear electrode 4.