The present invention provides an anode active material and a method for preparing the same, wherein the anode active material has a core-shell structure having formula (MOx-Liy)-C (here, M is a metal (or metalloid), x is greater than 0 and less than 1.5, and y is greater than 0 and less than 4) and including a core part containing an alloy of a metal (or metalloid) oxide-Li (MOx-Liy) and a shell part containing a carbon material coated on a surface of the core part, wherein the shell part contains lithium in an amount less than 5 atm % in the surface and the inner portion thereof. The anode active material can provide high capacity, excellent cycle characteristics, excellent volume expansion control capability, and high initial efficiency.

The present invention provides an anode active material and a method for preparing the same, wherein the anode active material has a core-shell structure having formula (MOx-Liy)-C (here, M is a metal (or metalloid), x is greater than 0 and less than 1.5, and y is greater than 0 and less than 4) and including a core part containing an alloy of a metal (or metalloid) oxide-Li (MOx-Liy) and a shell part containing a carbon material coated on a surface of the core part, wherein the shell part contains lithium in an amount less than 5 atm % in the surface and the inner portion thereof. The anode active material can provide high capacity, excellent cycle characteristics, excellent volume expansion control capability, and high initial efficiency.

A method for the preparation of an electrode comprising a substrate made of an aluminium based material, vertically aligned carbon nanotubes and an electrically conductive polymer matrix, the method comprising the following successive steps: (a) synthesising, on a substrate made of an aluminium based material, a carpet of vertically aligned carbon nanotubes according to the technique of CVD (Chemical Vapour Deposition) at a temperature less than or equal to 650° C.; (b) electrochemically depositing the polymer matrix on the carbon nanotubes from an electrolyte solution including at least one precursor monomer of the matrix, at least one ionic liquid and at least one protic or aprotic solvent. Further disclosed is the prepared electrode and a device for storing and returning electricity such as a supercapacitor comprising the electrode.

A method for the preparation of an electrode comprising a substrate made of an aluminium based material, vertically aligned carbon nanotubes and an electrically conductive polymer matrix, the method comprising the following successive steps: (a) synthesising, on a substrate made of an aluminium based material, a carpet of vertically aligned carbon nanotubes according to the technique of CVD (Chemical Vapour Deposition) at a temperature less than or equal to 650° C.; (b) electrochemically depositing the polymer matrix on the carbon nanotubes from an electrolyte solution including at least one precursor monomer of the matrix, at least one ionic liquid and at least one protic or aprotic solvent. Further disclosed is the prepared electrode and a device for storing and returning electricity such as a supercapacitor comprising the electrode.

This invention relates to particulate electroactive materials consisting of a plurality of composite particles, wherein the composite particles comprise a plurality of silicon nanoparticles dispersed within a conductive carbon matrix. The particulate material comprises 40 to 65 wt % silicon, at least 6 wt % and less than 20% oxygen, and has a weight ratio of the total amount of oxygen and nitrogen to silicon in the range of from 0.1 to 0.45 and a weight ratio of carbon to silicon in the range of from 0.1 to 1. The particulate electroactive materials are useful as an active component of an anode in a metal ion battery.

The present application discloses a composite graphite material, a secondary battery, an apparatus and a preparation method thereof. The composite graphite material includes a core material and a coating layer coating at least a part of the surface of the core material, the core material including graphite; wherein the absolute value K of zeta potential of the composite graphite material in deionized water with a pH of 7 is at least 20 mV. The use of the composite graphite material provided by the present application can improve the cohesion and bonding force of the negative electrode plate, thereby reducing the cyclic expansion of the secondary battery.

Systems and methods are provided for high volume roll-to-roll direct coating of electrodes for silicon-dominant anode cells. A slurry that includes silicon particles and a binder material may be applied to a current collector film, and the slurry may be processed to form a precursor composite film coated on the current collector film. The current collector film with the coated precursor composite film may be rolled into a precursor composite roll. A heat treatment may be applied to the current collector film with the coated precursor composite film in an environment including nitrogen gas, to convert the coated precursor composite film to a pyrolyzed composite film coated on the current collector film. The heat treatment may include applying the heat treatment to the precursor composite roll in whole and/or applying the heat treatment to the current collector film with the coated precursor composite film as it is continuously fed.

Systems and methods are provided for high volume roll-to-roll direct coating of electrodes for silicon-dominant anode cells. A slurry that includes silicon particles and a binder material may be applied to a current collector film, and the slurry may be processed to form a precursor composite film coated on the current collector film. The current collector film with the coated precursor composite film may be rolled into a precursor composite roll. A heat treatment may be applied to the current collector film with the coated precursor composite film in an environment including nitrogen gas, to convert the coated precursor composite film to a pyrolyzed composite film coated on the current collector film. The heat treatment may include applying the heat treatment to the precursor composite roll in whole and/or applying the heat treatment to the current collector film with the coated precursor composite film as it is continuously fed.

An exemplary embodiment of the present invention provides a spiral-wound electrode assembly including: a negative electrode and a positive electrode, each of which is configured to include a substrate, and a first composite material and a second composite material formed on opposite surfaces of the substrate; and a separator disposed between the negative electrode and the anode, wherein the first composite material of the negative electrode is disposed farther away from a center of the electrode assembly than the second composite material of the negative electrode, and the first composite material of the negative electrode is oriented with respect to a first surface of the substrate of the negative electrode.

An exemplary embodiment of the present invention provides a spiral-wound electrode assembly including: a negative electrode and a positive electrode, each of which is configured to include a substrate, and a first composite material and a second composite material formed on opposite surfaces of the substrate; and a separator disposed between the negative electrode and the anode, wherein the first composite material of the negative electrode is disposed farther away from a center of the electrode assembly than the second composite material of the negative electrode, and the first composite material of the negative electrode is oriented with respect to a first surface of the substrate of the negative electrode.