High-energy-density lithium ion battery

Abstract

The invention relates to a high-energy density lithium ion battery. A positive electrode including one or more of the following components: LiCoO2, Li(NixMnyCo1-x-y)O2 (x is greater than or equal to 0and less than or equal to 1, y is greater than or equal to 0 and less than or equal to 1), Li(NixCoyAl1-x-y)O2 (x is greater than or equal to 0 and less than or equal to 1, y is greater than or equalto 0 and less than or equal to 1), Li2MnO4, LiNi0.5Mn0.5O2, LiNi0.5Mn1.5O4, LiMPO4, and aLi2MnO3.(1-a)Li(NixMnyCo<1-x-y>)O2 (x is greater than or equal to 0 and less than or equal to 1, and y is greater than or equal to 0 and less than or equal to 1). The negative electrode comprises surface-modified silicon particles, a carbon conductive agent capable of forming a conductive network, an organicpolymer binder with high tensile strength and high elastic deformation characteristics, and a current collector substrate beneficial to electron conduction. The energy density of the battery can be improved, the rate capability and the low-temperature performance of the battery are improved, and the safety performance is better.

Description

technical field

[0001] The invention relates to the field of lithium ion batteries, in particular to a high energy density lithium ion battery. Background technique

[0002] In recent years, with the gradual consumption of traditional fossil energy and the increasingly serious problem of global warming, people are increasingly aware of the importance of new energy in the future society. In all new energy systems, solar energy, wind energy, water energy, nuclear energy, etc. do not have convenient mobility; and lithium-ion batteries, as a portable form of energy storage, have their specific irreplaceability in practical applications So it is widely used.

[0003] In 2017, before China’s National Development and Reform Commission stated that it would stop selling domestic traditional fuel vehicles in 2030, many countries had already announced a timetable for a complete ban on the sale of fuel vehicles: Britain and France set the target time for a complete ban on the sale of t...

Examples

Embodiment 1

[0116] The negative electrode formula is replaced by: polysilicon particles (median particle size D50=0.8 micron, maximum particle size D100=2.5 ​​micron) coated with carbon by chemical vapor deposition of the negative active material and conductive agent multi-armed carbon nanotubes, conductive graphite, The mass ratio of thickener carboxymethylcellulose sodium (CMCNa), sodium polyacrylate (PAANa), binder styrene-butadiene rubber (SBR), and polystyrene acrylic acid copolymer is 80:2:3:3:4: 5:3; electrode porosity is 35%. Among them, the powder obtained by crushing polysilicon is coated with carbon on the surface by chemical vapor deposition: the polysilicon powder is placed in the center of the tube furnace, and acetylene is introduced as the precursor of the carbon coating layer, and the surface coating is obtained by heating at 940°C for 2.5 hours. Carbon-coated polysilicon powder. The amount of carbon coated on the surface of silicon particles is 4.5%.

[0117] figure 1...

Embodiment 2

[0121] The negative electrode formula is replaced by: polysilicon particles (median particle size D50=0.8 micron, maximum particle size D100=2.5 ​​micron) coated with carbon by chemical vapor deposition of the negative active material and conductive agent multi-armed carbon nanotubes, conductive graphite, The mass ratio of thickener carboxymethylcellulose sodium (CMCNa), sodium polyacrylate (PAANa), binder styrene-butadiene rubber (SBR), and polystyrene acrylic acid copolymer is 80:2:3:3:4: 5:3; electrode porosity is 35%. Among them, the powder obtained by crushing polysilicon is coated with carbon on the surface by chemical vapor deposition: the polysilicon powder is placed in the center of the tube furnace, and acetylene is introduced as the precursor of the carbon coating layer, and the surface coating is obtained by heating at 940°C for 2.5 hours. Carbon-coated polysilicon powder. The amount of carbon coated on the surface of silicon particles is 4.5%.

[0122] After tes...

Embodiment 3

[0124] The negative electrode formula is replaced by: polysilicon particles (median particle size D50=0.8 micron, maximum particle size D100=2.5 ​​micron) coated with carbon by chemical vapor deposition of the negative active material and conductive agent multi-armed carbon nanotubes, conductive graphite, The mass ratio of thickener carboxymethylcellulose sodium (CMCNa), sodium polyacrylate (PAANa), binder styrene-butadiene rubber (SBR), and polystyrene acrylic acid copolymer is 80:2:3:3:4: 5:3; electrode porosity is 35%. Among them, the powder obtained by crushing polysilicon is coated with carbon on the surface by chemical vapor deposition: the polysilicon powder is placed in the center of the tube furnace, and acetylene is introduced as the precursor of the carbon coating layer, and the surface coating is obtained by heating at 940°C for 2.5 hours. Carbon-coated polysilicon powder. The amount of carbon coated on the surface of silicon particles is 4.5%.

[0125] After tes...

technical field

[0001] The invention relates to the field of lithium ion batteries, in particular to a high energy density lithium ion battery. Background technique

[0002] In recent years, with the gradual consumption of traditional fossil energy and the increasingly serious problem of global warming, people are increasingly aware of the importance of new energy in the future society. In all new energy systems, solar energy, wind energy, water energy, nuclear energy, etc. do not have convenient mobility; and lithium-ion batteries, as a portable form of energy storage, have their specific irreplaceability in practical applications So it is widely used.

[0003] In 2017, before China’s National Development and Reform Commission stated that it would stop selling domestic traditional fuel vehicles in 2030, many countries had already announced a timetable for a complete ban on the sale of fuel vehicles: Britain and France set the target time for a complete ban on the sale of t...

Examples

Embodiment 1

[0116] The negative electrode formula is replaced by: polysilicon particles (median particle size D50=0.8 micron, maximum particle size D100=2.5 ​​micron) coated with carbon by chemical vapor deposition of the negative active material and conductive agent multi-armed carbon nanotubes, conductive graphite, The mass ratio of thickener carboxymethylcellulose sodium (CMCNa), sodium polyacrylate (PAANa), binder styrene-butadiene rubber (SBR), and polystyrene acrylic acid copolymer is 80:2:3:3:4: 5:3; electrode porosity is 35%. Among them, the powder obtained by crushing polysilicon is coated with carbon on the surface by chemical vapor deposition: the polysilicon powder is placed in the center of the tube furnace, and acetylene is introduced as the precursor of the carbon coating layer, and the surface coating is obtained by heating at 940°C for 2.5 hours. Carbon-coated polysilicon powder. The amount of carbon coated on the surface of silicon particles is 4.5%.

[0117] figure 1...

Embodiment 2

[0121] The negative electrode formula is replaced by: polysilicon particles (median particle size D50=0.8 micron, maximum particle size D100=2.5 ​​micron) coated with carbon by chemical vapor deposition of the negative active material and conductive agent multi-armed carbon nanotubes, conductive graphite, The mass ratio of thickener carboxymethylcellulose sodium (CMCNa), sodium polyacrylate (PAANa), binder styrene-butadiene rubber (SBR), and polystyrene acrylic acid copolymer is 80:2:3:3:4: 5:3; electrode porosity is 35%. Among them, the powder obtained by crushing polysilicon is coated with carbon on the surface by chemical vapor deposition: the polysilicon powder is placed in the center of the tube furnace, and acetylene is introduced as the precursor of the carbon coating layer, and the surface coating is obtained by heating at 940°C for 2.5 hours. Carbon-coated polysilicon powder. The amount of carbon coated on the surface of silicon particles is 4.5%.

[0122] After tes...

Embodiment 3

[0124] The negative electrode formula is replaced by: polysilicon particles (median particle size D50=0.8 micron, maximum particle size D100=2.5 ​​micron) coated with carbon by chemical vapor deposition of the negative active material and conductive agent multi-armed carbon nanotubes, conductive graphite, The mass ratio of thickener carboxymethylcellulose sodium (CMCNa), sodium polyacrylate (PAANa), binder styrene-butadiene rubber (SBR), and polystyrene acrylic acid copolymer is 80:2:3:3:4: 5:3; electrode porosity is 35%. Among them, the powder obtained by crushing polysilicon is coated with carbon on the surface by chemical vapor deposition: the polysilicon powder is placed in the center of the tube furnace, and acetylene is introduced as the precursor of the carbon coating layer, and the surface coating is obtained by heating at 940°C for 2.5 hours. Carbon-coated polysilicon powder. The amount of carbon coated on the surface of silicon particles is 4.5%.

[0125] After tes...

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