阅读说明：本技术 二次电池和包含二次电池的装置 (Secondary battery and device including the same ) 是由 沈睿 马建军 何立兵 于 2020-03-27 设计创作，主要内容包括：本申请公开了一种二次电池和包含二次电池的装置。二次电池包括正极极片和负极极片,所述正极极片包括正极集流体以及设置在所述正极集流体至少一个表面上且包括正极活性材料的正极膜片,所述负极极片包括负极集流体以及设置在所述负极集流体至少一个表面上且包括负极活性材料的负极膜片,其中,所述正极活性材料包括层状锂过渡金属氧化物及其改性化合物中的一种或几种,所述负极活性材料包括人造石墨和天然石墨,且所述负极极片满足：0.02≤I-(3R(012))/I-(2H(100))≤0.18；或者,所述正极活性材料包括橄榄石结构的含锂磷酸盐及其改性化合物中的一种或几种,所述负极活性材料包括人造石墨和天然石墨,且所述负极极片满足：0.04≤I-(3R(012))/I-(2H(100))≤0.22。(Disclosed are a secondary battery and a device including the same. The secondary battery comprises a positive pole piece and a negative pole piece, wherein the positive pole piece comprises a positive current collector and is arranged on at least one surface of the positive current collector and comprises a positive active material, the negative pole piece comprises a negative current collector and is arranged on at least one surface of the negative current collector and comprises a negative active material, wherein the positive active material comprises one or more of layered lithium transition metal oxide and modified compounds thereof, the negative active material comprises artificial graphite and natural graphite, and the negative pole piece meets the following requirements: i is more than or equal to 0.02 3R(012) /I 2H(100) Less than or equal to 0.18; or the positive active material comprises one or more of olivine-structured lithium-containing phosphate and modified compounds thereof, the negative active material comprises artificial graphite and natural graphite, and the negative pole piece meets the following requirements: 0.04≤I 3R(012) /I 2H(100) ≤0.22。)

A secondary battery comprises a positive pole piece and a negative pole piece, wherein the positive pole piece comprises a positive current collector and a positive diaphragm which is arranged on at least one surface of the positive current collector and comprises a positive active material, the negative pole piece comprises a negative current collector and a negative diaphragm which is arranged on at least one surface of the negative current collector and comprises a negative active material, wherein,

the positive active material comprises one or more of layered lithium transition metal oxide and modified compound thereof;

the negative active material comprises artificial graphite and natural graphite, and the negative pole piece meets the following requirements: i is more than or equal to 0.02_3R(012)/I _2H(100)0.18 or less, preferably 0.04 or less I₃R ₍₀₁₂₎/I _2H(100)≤0.12；

Wherein, the I_3R(012)Is the peak intensity of the X-ray diffraction peak of the crystal face of the 3R phase 012 of the negative active material in the negative pole piece, and the I_2H(100)As in the negative electrode sheetPeak intensity of X-ray diffraction peak of 2H phase 100 crystal plane of the negative electrode active material.

The secondary battery of claim 1, wherein the negative pole piece further satisfies: i is more than or equal to 0.02_3R(101)/I _2H(101)Less than or equal to 0.18; preferably, 0.04 ≦ I_3R(101)/I _2H(101)≤0.12；

Wherein, the I_3R(101)Is the peak intensity of the X-ray diffraction peak of the crystal face of the 3R phase 101 of the negative active material in the negative pole piece, and I_2H(101)The peak intensity of the X-ray diffraction peak of the 2H phase 101 crystal face of the negative electrode active material in the negative electrode pole piece.

The secondary battery according to claim 1 or 2, wherein the mass ratio of the natural graphite in the negative electrode active material is 50% or less, preferably 15% to 25%.

The secondary battery according to any one of claims 1 to 3, wherein the average particle diameter D of the negative electrode active material_V50 is 11 to 15 μm, preferably 12 to 14 μm.

The secondary battery according to any one of claims 1 to 4, wherein the tap density of the negative active material is not less than 1.1g/cm³Preferably 1.1g/cm³～1.15g/cm ³(ii) a And/or the presence of a gas in the gas,

the graphitization degree of the negative electrode active material is 92-96%, and preferably 93-95%.

The secondary battery according to any one of claims 1 to 5, wherein the negative electrode membrane has an areal density of 10mg/cm²～13mg/cm ²Preferably 10.5mg/cm²～11.5mg/cm ²(ii) a And/or the presence of a gas in the gas,

the compacted density of the negative electrode diaphragm is 1.6g/cm ³～1.8g/cm ³Preferably 1.65g/cm³～1.7g/cm ³。

The secondary battery according to any one of claims 1 to 6, wherein the layered lithium transition metal oxide comprises one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and modified compounds thereof.

A secondary battery comprises a positive pole piece and a negative pole piece, wherein the positive pole piece comprises a positive current collector and a positive diaphragm which is arranged on at least one surface of the positive current collector and comprises a positive active material, the negative pole piece comprises a negative current collector and a negative diaphragm which is arranged on at least one surface of the negative current collector and comprises a negative active material, wherein,

the positive active material comprises one or more of olivine-structured lithium-containing phosphate and modified compounds thereof;

the negative active material comprises artificial graphite and natural graphite, and the negative pole piece meets the following requirements: i is more than or equal to 0.04_3R(012)/I _2H(100)0.22 or less, preferably 0.06 or less I_3R(012)/I _2H(100)≤0.18；

Wherein, the I_3R(012)Is the peak intensity of the X-ray diffraction peak of the crystal face of the 3R phase 012 of the negative active material in the negative pole piece, and the I_2H(100)The peak intensity of the X-ray diffraction peak of the 2H phase 100 crystal face of the negative electrode active material in the negative electrode pole piece.

The secondary battery of claim 8, wherein the negative pole piece further satisfies: i is more than or equal to 0.04_3R(101)/I _2H(101)Less than or equal to 0.22; preferably, 0.06 ≦ I_3R(101)/I _2H(101)≤0.18；

Wherein, the I_3R(101)Is 3R of the negative active material in the negative pole piecePeak intensity of X-ray diffraction peak of phase 101 crystal plane, said I_2H(101)The peak intensity of the X-ray diffraction peak of the 2H phase 101 crystal face of the negative electrode active material in the negative electrode pole piece.

The secondary battery according to claim 8 or 9, wherein the natural graphite is present in the negative active material at a mass ratio of 20% or more, preferably 35% to 50%.

The secondary battery according to any one of claims 8 to 10, wherein the average particle diameter D of the negative electrode active material_V50 is 15 to 19 μm, preferably 16 to 18 μm.

The secondary battery according to any one of claims 8 to 11, wherein the tap density of the negative electrode active material is < 1.1g/cm³Preferably 1.0g/cm³～1.09g/cm ³(ii) a And/or the presence of a gas in the gas,

the graphitization degree of the negative active material is 92-95%, and preferably 93-94%.

The secondary battery according to any one of claims 8 to 12, wherein the negative electrode membrane has an areal density of 7mg/cm²～10mg/cm ²Preferably 7mg/cm²～8mg/cm ²(ii) a And/or the presence of a gas in the gas,

the compacted density of the negative electrode diaphragm is 1.5g/cm³～1.7g/cm ³Preferably 1.55g/cm³～1.6g/cm ³。

The secondary battery according to any one of claims 8 to 13, wherein the olivine-structured lithium-containing phosphate includes one or more of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, and a modified compound thereof.

A device comprising the secondary battery according to any one of claims 1 to 14.