Provided is a lithium ion battery whose manufacturing process is simple and which has high energy density and heat resistance. A lithium ion battery capable of storing and releasing lithium ions, and being provided with a separator between a positive electrode and a negative electrode having irreversible capacity at the initial charge/discharge, and having a structure in which void portions in the separator are filled with a nonaqueous electrolytic solution including lithium ions, wherein a positive electrode active material contained in the positive electrode has a first charge-discharge efficiency of 80% to 90% when charged/discharged using metal Li as an counter electrode; a negative electrode active material contained in the negative electrode includes a mixed material of a silicon compound and a carbon material; in the negative electrode, lithium corresponding to an irreversible capacity at the initial charge/discharge is not doped; a capacity ratio of the negative electrode to the positive electrode at the initial electric charge capacity of the positive electrode and the negative electrode is 0.95 or more and 1 or less; the positive electrode binder contained in the positive electrode is an aqueous binder; the negative electrode binder contained in the negative electrode is a polyimide; and the nonaqueous electrolyte contains lithium bis(oxalate) borate.

Although a material containing silicon attracts attention as a high-capacity negative electrode active material, it has a problem of having a large irreversible capacity at the initial charge and discharge cycle.

As a negative electrode active material, a particle which is a mixture of silicon, lithium metasilicate, and lithium oxide is used. Because lithium metasilicate and lithium oxide are already contained in the particle of the negative electrode active material, a compound containing lithium and oxygen (lithium orthosilicate and lithium metasilicate), which is a cause of the irreversible capacity at the initial charge, is not generated any more. This enables a negative electrode active material with a small irreversible capacity.

A method for making a vanadium pentoxide-based active material for a cathode of an alkali metal ion battery includes steps of: a) preparing an aqueous solution of a triazine derivative of Formula (I) ##STR00001## wherein each R independently represents hydrogen or an amino group; and b) adding vanadium pentoxide to the aqueous solution of the triazine derivative under stirring, so as to permit condensation among hydrolyzed vanadium pentoxide along with self-assembly of the triazine derivatives to obtain a reaction solution containing the active material.

To produce a silicon oxide-based negative electrode material containing Li and having uniform distribution of a Li concentration both inside particles and between particles although a C-coating film is formed on a surface, and yet in which generation of SiC is suppressed. A SiO gas and a Li gas are simultaneously generated by heating a Si-lithium silicate-containing raw material under reduced pressure. The Si-lithium silicate-containing raw material includes Si, Li, and O, in which a part of the Si is present as a Si simple substance and the Li is present as lithium silicate. By cooling the generated gases, Li-containing silicon oxide having an average composition of SiLi.sub.xO.sub.y (0.05<x<y and 0.5<y<1.5 are satisfied) is prepared. After adjusting the particle size, a C-coating film having an average film thickness of 0.5 to 10 nm is formed on a surface of particles at a treatment temperature of 900° C. or less.

A pre-lithiated silicon anode comprising a PVDF binder at 5-12 wt. % for use in a Li-ion cell is provided. In particular instances, a conductive additive may be added at less than 5 wt. %. The Si anode with PVDF binder is pre-lithiated prior to cell assembly and following Si anode fabrication. The combination of pre-lithiation and PVDF in the Si anode for use in a rechargeable Li-ion cell shows the unexpected result of extending the cycle life.

To provide a negative electrode for a secondary battery and a secondary battery having a large energy density and a capacity less likely to reduce even after repeated charging and discharging, and manufacturing methods thereof. The above-described problem is solved by a negative electrode for a secondary battery (3) comprising a negative electrode active material layer (3′) including at least a silicon-based active material and a binder, and a negative electrode current collector (14) having a structural form in which the silicon-based active material has an amorphous region including lithium and island-shaped lithium carbonate is distributed in the amorphous region. This negative electrode for a secondary battery (3) is manufactured by a method including a step of forming a negative electrode active material layer (3′) including a Si-based active material and a binder, and a predoping step of bringing an electrolytic solution (5) containing Li into contact with the negative electrode active material layer (3′), applying pressure, and introducing Li ions by an electrochemical method.

A dendrite penetration-resistant layer for a rechargeable alkali metal battery, comprising multiple graphene sheets or platelets or exfoliated graphite flakes that are chemically bonded by a lithium- or sodium-containing species to form an integral layer that prevents dendrite penetration through the integral layer, wherein the lithium-containing species is selected from Li.sub.2CO.sub.3, Li.sub.2O, Li.sub.2C.sub.2O.sub.4, LiOH, LiX, ROCO.sub.2Li, HCOLi, ROLi, (ROCO.sub.2Li).sub.2, (CH.sub.2OCO.sub.2Li).sub.2, Li.sub.2S, Li.sub.xSO.sub.y, Na.sub.2CO.sub.3, Na.sub.2O, Na.sub.2C.sub.2O.sub.4, NaOH, NaX, ROCO.sub.2Na, HCONa, RONa, (ROCO.sub.2Na).sub.2, (CH.sub.2OCO.sub.2Na).sub.2, Na.sub.2S, Na.sub.xSO.sub.y, or a combination thereof, wherein X=F, Cl, I, or Br, R=a hydrocarbon group, x=0-1, y=1-4. Also provided is a process for producing a dendrite penetration-resistant layer based on the principle of electrochemical decomposition of an electrolyte in the presence of multiple graphene sheets.

The present invention relates to a hierarchical composite structure comprising an open cell graphene foam or graphene-like foam, wherein the graphene foam or graphene-like foam is coated with a conductive nanoporous spongy structure and wherein at least 10% v/v of the hollow of the pores of the graphene foam or graphene-like foam is filled with the conductive nanoporous spongy structure. The invention also relates to a process for preparing a hierarchical composite structure wherein a conductive nanoporous spongy structure is electrodeposited so as to coat the open-cell graphene foam or graphene-like foam and to partially fill the hollow of the pores of the graphene foam or graphene-like foam.

An electrode manufacturing apparatus dopes an active material in a strip-shaped electrode precursor having a layer including the active material with alkali metal. The electrode manufacturing apparatus includes a doping bath configured to store a solution including alkali metal ions; a conveyor unit configured to convey the electrode precursor along a path passing through the doping bath; a counter electrode unit housed in the doping bath and comprising a conductive base material and an alkali metal-containing plate arranged on the conductive base material; and a connection unit configured to electrically connect the electrode precursor and the counter electrode unit. A distance between the alkali metal-containing plate and the electrode precursor becomes greater as a measurement position of the distance becomes closer to a connection position in which the electrode precursor and the connection unit connect each other.

Disclosed herein are methods of making an electrode. The method includes contacting an electrode material with a mixture that includes an alkali metal, an organic solvent, and an aromatic compound. Also disclosed herein are methods of making a battery that includes an electrode provided by the disclosed methods.