Disclosed is a hybrid electrochemical cell with a first conductor having at least one portion that is both a first capacitor electrode and a first battery electrode. The hybrid electrochemical cell further includes a second conductor having at least one portion that is a second capacitor electrode and at least one other portion that is a second battery electrode. An electrolyte is in contact with both the first conductor and the second conductor. In some embodiments, the hybrid electrochemical cell further includes a separator between the first conductor and the second conductor to prevent physical contact between the first conductor and the second conductor, while facilitating ion transport between the first conductor and the second conductor.

Disclosed is a hybrid electrochemical cell with a first conductor having at least one portion that is both a first capacitor electrode and a first battery electrode. The hybrid electrochemical cell further includes a second conductor having at least one portion that is a second capacitor electrode and at least one other portion that is a second battery electrode. An electrolyte is in contact with both the first conductor and the second conductor. In some embodiments, the hybrid electrochemical cell further includes a separator between the first conductor and the second conductor to prevent physical contact between the first conductor and the second conductor, while facilitating ion transport between the first conductor and the second conductor.

A cathode material, containing a crystal with a superlattice structure, is provided. A chemical formula of the crystal is xLi.sub.2MO.sub.3.(1-x)LiNi.sub.aCo.sub.bMn.sub.(1-a-b)O.sub.2, where 0<x≤0.1, 0.8≤a<1, b≤0.1, and M is selected from one or more of Mn, Co, and Ni. A preparation method of the cathode material and a battery or a capacitor containing the cathode material are also provided.

A cathode material, containing a crystal with a superlattice structure, is provided. A chemical formula of the crystal is xLi.sub.2MO.sub.3.(1-x)LiNi.sub.aCo.sub.bMn.sub.(1-a-b)O.sub.2, where 0<x≤0.1, 0.8≤a<1, b≤0.1, and M is selected from one or more of Mn, Co, and Ni. A preparation method of the cathode material and a battery or a capacitor containing the cathode material are also provided.

Electrolytes and electrolyte additives for energy storage devices comprising functional thiophene compounds are disclosed. The energy storage device comprises a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, an electrolyte, and at least one electrolyte additive selected from a thiophene compound.

Electrolytes and electrolyte additives for energy storage devices comprising functional thiophene compounds are disclosed. The energy storage device comprises a first electrode and a second electrode, wherein at least one of the first electrode and the second electrode is a Si-based electrode, a separator between the first electrode and the second electrode, an electrolyte, and at least one electrolyte additive selected from a thiophene compound.

Disclosed here is a method for producing a graphene macro-assembly (GMA)-fullerene composite, comprising providing a mixture of graphene oxide and water, adding a hydroxylated fullerene to the mixture, and forming a gel of the hydroxylated fullerene and the mixture. Also described are a GMA-fullerene composite produced, an electrode comprising the GMA-fullerene composite, and a supercapacitor comprising the electrode.

Disclosed here is a method for producing a graphene macro-assembly (GMA)-fullerene composite, comprising providing a mixture of graphene oxide and water, adding a hydroxylated fullerene to the mixture, and forming a gel of the hydroxylated fullerene and the mixture. Also described are a GMA-fullerene composite produced, an electrode comprising the GMA-fullerene composite, and a supercapacitor comprising the electrode.

Provided is a method for manufacturing an electrode by doping an active material included a layer of an electrode precursor with alkali metal. The electrode precursor and a counter electrode member are brought into contact with a solution containing an alkali metal ion in a dope bath. The counter electrode member includes a conductive base material, an alkali metal-containing plate, and a member having an opening. The member having the opening is located between the conductive base material and the alkali metal-containing plate. The member having the opening is, for example, a resin film having an opening.

Provided is a method for manufacturing an electrode by doping an active material included a layer of an electrode precursor with alkali metal. The electrode precursor and a counter electrode member are brought into contact with a solution containing an alkali metal ion in a dope bath. The counter electrode member includes a conductive base material, an alkali metal-containing plate, and a member having an opening. The member having the opening is located between the conductive base material and the alkali metal-containing plate. The member having the opening is, for example, a resin film having an opening.