Murata Manufacturing Co., Ltd.

National Institute of Advanced Industrial Science and Technology

Masashi Higuchi

Masahiro Otsuka

Toru Kawai

Takuya Kenko

Tetsuo Sakai

Masahiro Yanagida

Masanori Morishita

Akihiro Yamano

A method of manufacturing a secondary battery that includes providing a secondary battery precursor having an electrode assembly with a cutout portion in a plan view thereof and an electrolyte accommodated in an outer package, the electrode assembly including a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode; erecting the secondary battery precursor so as to have an opening of the outer package arranged uppermost in a vertical direction in an erected state; and initially charging the secondary battery precursor such that gas generated in the secondary battery precursor is released from the opening of the outer package.

Method of manufacturing secondary battery including releasing gas generated during initial charging from opening of outer package

A method for manufacturing a secondary battery in which the preparation of at least one of a positive electrode and ta negative electrode includes forming an electrode material layer on a metal sheet material to serve as an electrode current collector, thereby providing an electrode precursor, and cutting out electrodes from the electrode precursor to form a plurality of electrodes. Each of the electrodes has a non-rectangular shape.

Method for manufacturing secondary battery

An electric storage device includes a case having a substantially rectangular shape including a cutout part. An electrode body is disposed in the case and includes a first electrode, a second electrode, and a separator disposed between the first and second electrodes. An electrolyte is located in the case and at least partially impregnating the electrode body. A first electrode terminal is located on a first part of a side surface of the case and is electrically connected to the first electrode by a first connection member which has elasticity in a direction extending from the first electrode terminal to the first electrode. A second electrode terminal is located on a second part of the side surface of the case and is electrically connected to the second electrode by a second elastic connection member which has elasticity in a direction extending from the second electrode terminal to the second electrode.

Electric storage device

An electrical storage device includes a case having first and second opposed main walls which face one another and at least one side wall coupled the first and second main walls. The case having a generally rectangular shape with outer corners and includes a cutout part having inner corners. An integrated electrode body is located in the case and is joined to the first main wall. The integrated body includes a first electrode, a second electrode, and a separator disposed between the first and second electrodes. The electrode body has a bending strength which is higher than a bending strength of the first main wall. An electrolyte fills the case.

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.

Lithium ion battery

An electrode laminate is located in a case. The electrode laminate has opposed first and second principal surfaces and opposed first and second lateral side surfaces. The electrode laminate includes a positive electrode having a planar main surface and first and second opposed lateral ends located on opposite lateral sides of its main surface, a negative electrode having a planar main surface and first and second opposed lateral ends located on opposite lateral sides of its main surface, the main surface of the positive electrode opposing the main surface of the negative electrode. A separator is located between the opposed main surfaces of the positive and negative electrodes and has first and second lateral ends extending laterally outward from the first and second lateral ends of the positive and negative electrodes, respectively. At least a tip of the first and second lateral ends of the separator are bent in a direction towards the first principal surface of the electrode laminate. An electrolyte is impregnated in the separator.

Growing community of inventors

Nagaokakyo, Japan

Masashi Higuchi