Nec Corporation

Nec Energy Devices, Ltd.

Envision Aesc Japan Ltd.

Jiro Iriyama

Daisuke Kawasaki

Hironori Yamamoto

Tatsuji Numata

Kentaro Nakahara

Koji Utsugi

Ryuichi Kasahara

Tetsuya Kajita

Mitsuhiro Mori

Shigeyuki Iwasa

Yukiko Morioka

Masaharu Satoh

Tamaki Miura

Masahiro Suguro

Mariko Miyachi

Kazuhiko Inoue

Hiroo Takahashi

Masato Shirakata

Yutaka Bannai

Shin Serizawa

Hidemasa Kawai

Kenichi Shimura

Shinako Kaneko

Ikiko Yamazaki

Emiko Fujii

Noboru Yoshida

Makihiro Otohata

Kazuaki Matsumoto

Kenji Ohara

Ikiko Shimanuki

Sadahiko Miura

Yasutaka Kono

Yuki Kusachi

Shin Tanaka

Tomoyuki Ohta

Sigeyuki Iwasa

Tamaki Nakahashi

Satoshi Nagashima

Lithium ion secondary batteries are disclosed that include a positive electrode comprising a lithium nickel composite oxide as a positive electrode active material and a separator consisting of one or more layers selected from polyimide layer, polyamide layer, the battery having a low self-discharge failure rate even after long term storage. The lithium ion secondary batteries can include a positive electrode comprising a lithium nickel composite oxide and a separator consisting of one or more layers selected from polyimide layer, polyamide layer, and polyamide imide layer, wherein the battery comprises an acid and/or an acid anhydride in an electrolyte solution and/or a member in contact with the electrolyte solution.

Lithium-ion secondary battery

The object of an exemplary embodiment of the invention is to provide a lithium ion secondary battery having an excellent charge and discharge cycle property. An exemplary embodiment of the invention is a lithium ion secondary battery, comprising a battery assembly in which a positive electrode and a negative electrode are stacked through a separator and a package in which the battery assembly and an electrolyte are placed; wherein the negative electrode comprises a negative electrode collector which is composed of a metal and a negative electrode active material layer which is formed on the negative electrode collector and which comprises a negative electrode active material and a binder; wherein the negative electrode collector and the negative electrode active material layer have a crack which is formed so as to be communicated with each of them; and wherein the crack reaches an outer peripheral edge from an inside of the negative electrode.

Lithium ion secondary battery

The present invention relates to a lithium ion secondary battery comprising a positive electrode having a coating amount per unit area of 50 mg/cmor more and an electrode density of 3.3 g/cc or more and a negative electrode having a coating amount per unit area of 24 mg/cmor more and an electrode density of 1.5 g/cc or more, a separator having a shrinking ratio of 2% or less by heat treatment at 80&#xb0; C. for 6 hours, and an electrolyte solution comprising at least one sulfonic acid ester compound, and a ratio of a sulfur content in the central portion (As) and a sulfur content in the edge portion (Bs) of the positive electrode and the negative electrode, in each, is 0.7&#x2264;As/Bs&#x2264;1.1.

Lithium ion secondary battery and method for manufacturing same

A negative electrode active material comprising silicon oxide satisfying the following Equation 1 and Equation 2 when solid state NMR (Si-DDMAS) of silicon is measured for the silicon oxide after performing charging at least once is excellent in the performance as a negative electrode active material for a lithium secondary battery;0.42&#x2264;1/(1+2+3)&#x2264;0.55&#x2003;&#x2003;(Equation 1)0.21&#x2264;3/(1+2+3)&#x2264;0.26,&#x2003;&#x2003;(Equation 2)in which S1 is a sum of peak areas of a group of signals assigned to Si having a Si&#x2014;Si bond and having peaks at 0 to &#x2212;15 ppm, &#x2212;55 ppm, &#x2212;84 ppm and &#x2212;88 ppm, S2 is a sum of peak areas of a group of signals assigned to Si having a Si(OH)(OSi)(n=3, 4) structure and having peaks at &#x2212;100 ppm and &#x2212;120 ppm, and S3 is a sum of peak areas of a group of signals assigned to Si having a Si(OLi)(OSi)(n=0, 1, 2, 3) structure and having peaks at &#x2212;66 ppm, &#x2212;74 ppm, &#x2212;85 ppm and &#x2212;96 ppm.

Negative electrode active material, method for manufacturing same, and lithium secondary battery

The present invention relates to a lithium secondary battery, wherein a peak at 167 to 171 eV and a peak at 162 to 166 eV are present in XPS analysis of sulfur (S2p) of a positive electrode surface, and P169/P164 is in the range of 0.7 to 2.0 wherein the P 169/P 164 is the ratio between the intensity of the peak at 167 to 171 eV (P169) and the intensity of the peak at 162 to 166 eV (P164). The present invention can provide a lithium secondary battery having excellent cycle characteristics.

Lithium secondary battery

It is an object of the present invention to provide a method for producing a secondary battery in which water in the outer package can be removed even when the secondary battery includes an electrolytic solution containing a halogen-containing compound. The present exemplary embodiment is a method for producing a secondary battery including an electrolytic solution containing a supporting salt, a nonaqueous solvent, and a halogen-containing compound, an electrode assembly including a negative electrode and a positive electrode, and an outer package, the method including (1) disposing a first solution containing at least the supporting salt and the nonaqueous solvent, and the electrode assembly in the outer package; (2) charging the electrode assembly; (3) emitting from the outer package a gas generated by the charge; and (4) injecting a second solution including at least the halogen-containing compound into the outer package after the gas is emitted, wherein the first solution does not contain the halogen-containing compound, and the electrolytic solution includes the first solution and the second solution.

Method for producing secondary battery

The present invention provides a lithium secondary battery, wherein a peak at 167 to 171 eV and a peak at 160 to 164 eV are present in XPS analysis of sulfur on a negative electrode surface (S2p), and P169/P162 is in the range of 0.7 to 2.0 wherein the P169/P162 is the ratio between the intensity of the peak at 167 to 171 eV (P169) and the intensity of the peak at 160 to 164 eV (P162).

A control system for a lithium secondary battery measures a voltage V of a negative electrode that uses silicon oxide as a negative electrode active material, with respect to a lithium reference electrode and a discharge capacity Q of the lithium secondary battery during discharge of the lithium secondary battery; generates a V&#x2212;dQ/dV curve representing a relationship between dQ/dV, which is a proportion of an amount of change dQ in the discharge capacity Q to an amount of change dV in the voltage V, and the voltage V; calculates an intensity ratio of two peaks appearing on the V&#x2212;dQ/dV curve for two voltage values in the voltage V; and senses a state of the negative electrode utilizing the intensity ratio.

System and method for detecting a state of a lithium secondary battery by measuring a voltage of a negative electrode with respect to a reference electrode

An exemplary embodiment provides a lithium ion secondary battery using a high energy type anode, which enables long-life operation thereof. A secondary battery according to an exemplary embodiment comprises an electrode element in which a cathode and an anode are oppositely disposed, an electrolytic solution, and an outer packaging body which encloses the electrode element and the electrolytic solution inside; wherein the anode is formed by binding an anode active material, which comprises carbon material (a) that can absorb and desorb a lithium ion, metal (b) that can be alloyed with lithium, and metal oxide (c) that can absorb and desorb a lithium ion, to an anode collector with an anode binder; and wherein the electrolytic solution comprises a liquid medium which is hard to generate carbon dioxide at a concentration of 10 to 80 vol %.

Secondary battery

An object of the present invention is to provide a power storage device with excellent cycle property, employing a cathode containing a nitroxyl polymer. To attain the object in the present invention, in the power storage device employing a cathode comprising a nitroxyl polymer, a lithium or lithium alloy anode is used as an anode active material and the cathode is in direct contact with the anode.

Power storage device having a nitroxyl polymer in a cathode and a lithium or lithium alloy anode

Provided is a negative electrode active material for a lithium secondary cell, the material having the function of a binder for the active material, and being capable of stable reversible reactions with lithium. Also, provided are an extended-life lithium secondary cell having improved energy density and stable charge/discharge, and a method for producing the same. The negative electrode active material for a lithium secondary cell is polyimide represented by formula (1) (wherein R1 and R2 independently denote an alkyl, alkoxy, acyl, phenyl, or phenoxy group).

Negative electrode active material for lithium secondary cell, lithium secondary cell employing the same, and method for producing the same

There is provided a negative electrode for a nonaqueous electrolyte secondary battery in which when a battery is formed, the energy density is high, and moreover, the decrease in charge and discharge capacity is small even if charge and discharge are repeated. By using silicon oxide particles having a particle diameter in a particular range as a starting raw material, and heating these particles in the range of 850&#xb0; C. to 1050&#xb0; C., Si microcrystals are deposited on the surfaces of the particles. Then, by performing doping of Li, a structure comprising a plurality of protrusions having height and cross-sectional area in a particular range is formed on the surfaces. The average value of the height of the above protrusions is 2% to 19% of the average particle diameter of the above lithium-containing silicon oxide particles. By using the lithium-containing silicon oxide particles obtained by the above means as a negative electrode active material, a negative electrode for a nonaqueous electrolyte secondary battery is fabricated.

Negative electrode for nanaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery using the same, and method for manufacturing negative electrode for nonaqueous electrolyte secondary battery

An exemplary embodiment provides a lithium ion secondary battery using a high energy type anode, which enables long-life operation thereof. A secondary battery according to an exemplary embodiment comprises an electrode element in which a cathode and an anode are oppositely disposed, an electrolytic solution, and an outer packaging body which encloses the electrode element and the electrolytic solution inside; wherein the anode is formed by binding an anode active material, which comprises carbon material (a) that can absorb and desorb a lithium ion, metal (b) that can be alloyed with lithium, and metal oxide (c) that can absorb and desorb a lithium ion, to an anode collector with an anode binder; and wherein the electrolytic solution comprises a liquid medium which is hard to generate carbon dioxide at a concentration of 10 to 75 vol %.

In a lithium ion secondary battery including a positive electrode, a separator, and a negative electrode opposed to the positive electrode with an intervention of the separator, the negative electrode includes a negative electrode active material including a silicon compound, and a negative electrode binder including a particular polyimide, and lithium is occluded in both the negative electrode active material and the negative electrode binder even during discharge.

The object of an exemplary embodiment of the invention is to provide a negative electrode having excellent cycle property. An exemplary embodiment of the invention a method for doping and dedoping lithium for the first time after a negative electrode for a lithium secondary battery comprising silicon oxide as an active material is produced, comprising doping the lithium within the following current value range (A) and within the following doped amount range (B); current value range (A): a range of a current value in which a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve becomes maximum, wherein the V-dQ/dV curve represents a relationship between voltage V of the negative electrode with respect to a lithium reference electrode and dQ/dV that is a ratio of variation dQ of lithium dedoped amount Q in the negative electrode to variation dV of the voltage V, and doped amount range (B): a range of a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve.

Growing community of inventors

Tokyo, Japan

Jiro Iriyama