A low carbon footprint material is used to decrease the carbon dioxide emission for production of a high carbon footprint substance. A method of forming composite materials comprises providing a first high carbon footprint substance; providing a carbon nanomaterial produced with a carbon-footprint of less than 10 unit weight of carbon dioxide (CO.sub.2) emission during production of 1 unit weight of the carbon nanomaterial; and forming a composite comprising the high carbon footprint substance and from 0.001 wt % to 25 wt % of the carbon nanomaterial, wherein the carbon nanomaterial is homogeneously dispersed in the composite to reduce the carbon dioxide emission for producing the composite material relative to the high carbon footprint substance.

A negative electrode active material and a method for preparing a negative electrode active material, comprising preparing a silicon-based compound including SiO.sub.x, wherein 0.5<x<1.3, and forming a crystalline carbon coating layer on the silicon-based compound through a chemical vapor deposition method using an organometallic compound as a source, wherein the organometallic compound is at least any one selected from the group consisting of aluminum acetylacetonate, aluminum ethoxide, aluminum phenoxide, aluminum acetate, aluminum tributoxide, and a combination thereof.

A low carbon footprint material is used to decrease the carbon dioxide emission for production of a high carbon footprint substance. A method of forming composite materials comprises providing a first high carbon footprint substance; providing a carbon nanomaterial produced with a carbon-footprint of less than 10 unit weight of carbon dioxide (CO.sub.2) emission during production of 1 unit weight of the carbon nanomaterial; and forming a composite comprising the high carbon footprint substance and from 0.001 wt % to 25 wt % of the carbon nanomaterial, wherein the carbon nanomaterial is homogeneously dispersed in the composite to reduce the carbon dioxide emission for producing the composite material relative to the high carbon footprint substance.

A negative electrode active material and a method for preparing a negative electrode active material, comprising preparing a silicon-based compound including SiO.sub.x, wherein 0.5<x<1.3, and forming a crystalline carbon coating layer on the silicon-based compound through a chemical vapor deposition method using an organometallic compound as a source, wherein the organometallic compound is at least any one selected from the group consisting of aluminum acetylacetonate, aluminum ethoxide, aluminum phenoxide, aluminum acetate, aluminum tributoxide, and a combination thereof.

A Li/CFx primary battery having a lithium-based anode and a fluorinated carbon cathode. The fluorinated carbon cathode includes fluorinated carbon nanoparticles. The structure and size distribution of the carbon precursor carbon nanotubes are configured to provide improved battery performance. The fluorinated carbon nanoparticles can be formed by fluorinating carbon nanoparticles using a fluorine-based reactive gas at a temperature in the range from 300 to 600 C., and the fluorinated carbon nanoparticles can further be used to form the cathode of the primary battery. Producing the Li/CFx primary batter can also include heating the fluorinated carbon nanoparticles under an inert atmosphere before the fluorinated carbon nanoparticles are used to form the cathode of the primary battery.

A Li/CFx primary battery having a lithium-based anode and a fluorinated carbon cathode. The fluorinated carbon cathode includes fluorinated carbon nanoparticles. The structure and size distribution of the carbon precursor carbon nanotubes are configured to provide improved battery performance. The fluorinated carbon nanoparticles can be formed by fluorinating carbon nanoparticles using a fluorine-based reactive gas at a temperature in the range from 300 to 600 C., and the fluorinated carbon nanoparticles can further be used to form the cathode of the primary battery. Producing the Li/CFx primary batter can also include heating the fluorinated carbon nanoparticles under an inert atmosphere before the fluorinated carbon nanoparticles are used to form the cathode of the primary battery.

Provided is an internal hybrid electrochemical cell comprising: (A) a pseudocapacitance cathode comprising a cathode active material that contains a conductive carbon material and a porphyrin compound, wherein the porphyrin compound is bonded to or supported by the carbon material to form a redox pair for pseudocapacitance, wherein the carbon material is selected from activated carbon, activated carbon black, expanded graphite flakes, exfoliated graphite worms, carbon nanotube, carbon nanofiber, carbon fiber, a combination thereof; (B) a battery-like anode comprising lithium metal, lithium metal alloy, or a prelithiated anode active material (e.g. prelithiated Si, SiO, Sn, SnO.sub.2, etc.), and (C) a lithium-containing electrolyte in physical contact with the anode and the cathode; wherein the cathode active material has a specific surface area no less than 100 m.sup.2/g which is in direct physical contact with the electrolyte.

Provided is an internal hybrid electrochemical cell comprising: (A) a pseudocapacitance cathode comprising a cathode active material that contains a conductive carbon material and a porphyrin compound, wherein the porphyrin compound is bonded to or supported by the carbon material to form a redox pair for pseudocapacitance, wherein the carbon material is selected from activated carbon, activated carbon black, expanded graphite flakes, exfoliated graphite worms, carbon nanotube, carbon nanofiber, carbon fiber, a combination thereof; (B) a battery-like anode comprising lithium metal, lithium metal alloy, or a prelithiated anode active material (e.g. prelithiated Si, SiO, Sn, SnO.sub.2, etc.), and (C) a lithium-containing electrolyte in physical contact with the anode and the cathode; wherein the cathode active material has a specific surface area no less than 100 m.sup.2/g which is in direct physical contact with the electrolyte.

Provided is an internal hybrid electrochemical cell comprising: (A) a pseudocapacitance cathode comprising a cathode active material that contains both graphene sheets and a porphyrin complex, wherein said porphyrin complex is bonded to or supported by primary surfaces of said graphene sheets to form a redox pair for pseudocapacitance; (B) a battery-like anode comprising lithium metal, lithium metal alloy, or a prelithiated anode active material (e.g. prelithiated Si, SiO, Sn, SnO.sub.2, etc.), and (C) a lithium-containing electrolyte in physical contact with the anode and the cathode; wherein the cathode active material has a specific surface area no less than 100 m.sup.2/g which is in direct physical contact with the electrolyte.

Provided is an internal hybrid electrochemical cell comprising: (A) a pseudocapacitance cathode comprising a cathode active material that contains both graphene sheets and a porphyrin complex, wherein said porphyrin complex is bonded to or supported by primary surfaces of said graphene sheets to form a redox pair for pseudocapacitance; (B) a battery-like anode comprising lithium metal, lithium metal alloy, or a prelithiated anode active material (e.g. prelithiated Si, SiO, Sn, SnO.sub.2, etc.), and (C) a lithium-containing electrolyte in physical contact with the anode and the cathode; wherein the cathode active material has a specific surface area no less than 100 m.sup.2/g which is in direct physical contact with the electrolyte.