POSITIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERY AND LITHIUM ION SECONDARY BATTERY

• Main Authors: YAMAYA RYUTA, KYUSEKI HIROSHI
• Format: Patent
• Language: English; Japanese
• Published: 01.11.2018
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PROBLEM TO BE SOLVED: To provide a positive electrode material for a lithium ion secondary battery capable of reducing DC resistance and also to provide the lithium ion secondary battery.SOLUTION: Disclosed is a positive electrode material consisting of agglomerated secondary particles formed by agglomerating a plurality of primary particles of electrode active material particles consisting of a transition metal phosphate lithium compound having an olivine structure coated with a carbonaceous material. An arithmetic average roughness Ra of the agglomerated secondary particle surface observed by a three-dimensional scanning electron microscope is 3 nm or more and less than 15 nm.SELECTED DRAWING: None 【課題】直流抵抗を低減させることができるリチウムイオン二次電池用正極材料、及びリチウムイオン二次電池を提供する。【解決手段】炭素質材料で被覆されたオリビン構造の遷移金属リン酸リチウム化合物からなる電極活物質粒子の一次粒子が複数個凝集した凝集二次粒子からなる正極材料であって、三次元走査型電子顕微鏡で観察した凝集二次粒子表面の算術平均粗さＲａが３ｎｍ以上１５ｎｍ未満であることを特徴とするリチウムイオン二次電池用正極材料。【選択図】なし