Negative electrode active material of lithium secondary battery, secondary battery using the same, method for manufacturing the same

A method for manufacturing a negative electrode active material of lithium secondary battery, consisting of the steps of:

• mixing a coal-derived green coke and a coal-derived calcined coke to form a coke mixture, wherein a mass ratio of said green coke to said calcined coke in the coke mixture is in a range of from 90:10 to 10:90,
• adding a phosphorous compound to the coke mixture, said phosphorous compound being present in the coke mixture in an amount in a range of from 0.1:100 to 6.0:100 parts by mass relative to the mass of said green coke and said calcined coke;
• and
• firing the coke mixture with said phosphorous compound added therein.

A negative electrode active material of lithium secondary battery, consisting of:

• a coal-derived green coke;
• a coal-derived calcined coke, wherein a mass ratio of said green coke to said calcined coke is in a range of 90:10 to 10:90;
• a phosphorous compound, said phosphorus compound being present in an amount in a range of 0.1:100 to 6.0:100 relative to the mass of said green coke and said calcined coke;
• and
• a hydrogen content, said hydrogen content being present in an amount in a range of 3000 ppm or less.

A method for manufacturing a negative electrode active material of lithium secondary battery, consisting of the steps of:

• pulverizing a coal-derived green coke and a coal-derived calcined coke to make a powdery green coke and a powdery calcined coke,
• mixing said powdery green coke and said powdery calcined coke to form a coke mixture, wherein a mass ratio of said powdery green come to said powdery calcined coke in the coke mixture is in a range from 90:10 to 10:90,
• adding a phosphorous compound to the coke mixture, said phosphorous compound being present in the coke mixture in an amount in a range of from 0.1:100 to 6.0:100 parts by mass relative to the mass of said green coke and said calcined coke;
• and
• firing the coke mixture with said phosphorous compound added therein.