POSITIVE ELECTRODE STRUCTURE AND SECONDARY BATTERY

• Main Authors: HOSODA KAZUKI, SHINODA CHIHIRO, ICHINOSE YUMA, KITAHARA TAKAHIRO
• Format: Patent
• Language: English; Japanese
• Published: 09.04.2020
• Subjects: BASIC ELECTRIC ELEMENTS; CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES ORLIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

To provide a positive electrode structure having a configuration suitable for a lithium ion secondary battery capable of realizing increased capacity.SOLUTION: There is provided a positive electrode structure including a current collector and a positive electrode mixture layer provided on one side or both sides of the current collector. The positive electrode mixture layer has a thickness of 69 μm or more and a density of 3.0-5.0 g/cm, and contains a positive electrode active material and a binder. The positive electrode active material contains lithium-nickel composite oxide. The binder contains a fluorine-containing copolymer. The fluorine-containing copolymer contains a vinylidene fluoride unit and a fluorinated monomer unit (excluding a vinylidene fluoride unit). The fluorine-containing copolymer has a storage elastic modulus (E') of 100-1,100 MPa at 30°C and a storage elastic modulus (E') of 50-500 MPa at 60°C, as determined by dynamic viscoelasticity measurement.SELECTED DRAWING: None 【課題】高容量化を実現可能なリチウムイオン二次電池に適した構成を備える正極構造体を提供すること。【解決手段】集電体と、前記集電体の片面または両面に設けられた正極合剤層と、を備えており、前記正極合剤層の厚みが、６９μｍ以上であり、前記正極合剤層の密度が、３．０〜５．０ｇ／ｃｍ３であり、前記正極合剤層が、正極活物質およびバインダーを含有しており、前記正極活物質が、リチウム・ニッケル系複合酸化物を含有し、前記バインダーが、含フッ素共重合体を含有し、前記含フッ素共重合体が、ビニリデンフルオライド単位およびフッ素化単量体単位（ただし、ビニリデンフルオライド単位を除く）を含有し、前記含フッ素共重合体の動的粘弾性測定による３０℃における貯蔵弾性率（Ｅ'）が１００〜１１００ＭＰａであり、かつ、６０℃における貯蔵弾性率（Ｅ'）が５０〜５００ＭＰａである正極構造体を提供する。【選択図】 なし