Composite particle for electrode and electrochemical device
View Patent ↗A composite particle for electrode as an active material capable of forming an electrochemical device with excellent discharge capacities and rate characteristics is provided. A composite particle for electrode according to the present invention comprises a particulate core including at least one mother particle containing an electrode active material, and an electron-conducting layer which covers at least part of the surface of the particulate core, the electron-conducting layer including carbon and microparticles containing an electrode active material, and the microparticles having a particle size of 300 nm or less.
1. A composite particle for a cathode, the composite particle comprising:
a particulate core including at least one mother particle containing LiVOPO 4 ; and
an electron-conducting layer which covers at least part of a surface of said particulate core,
wherein:
said electron-conducting layer includes carbon and microparticles containing LiVOPO 4 ,
said microparticles have a particle size of 100 nm or less,
0.4 μm≦a particle size of the particulate core≦12 μm, and
the composite particle is a cathode active material for the cathode.
2. The composite particle according to claim 1 , wherein the composite particle has a coverage (L′/L) of 0.2 or more, where:
L′ represents a length of the electronic conducting layer formed on a circumference of the particulate core, and
L represents a length of the circumference of the particulate core.
3. The composite particle according to claim 1 , wherein the composite particle has a BET specific surface area of from 1.5 m 2 /g to 15.0 m 2 /g.
4. The composite particle for electrode according to claim 1 , wherein the electron conducting layer has an average thickness of from 10 to 500 nm.
5. An electrochemical device comprising:
a cathode comprising a composite particle, the composite particle comprising:
a particulate core including at least one mother particle containing LiVOPO 4 ; and
an electron-conducting layer which covers at least part of a surface of said particulate core,
wherein:
said electron-conducting layer includes carbon and microparticles containing LiVOPO 4 ,
said microparticles have a particle size of 100 nm or less,
0.4 μm≦a particle size of the particulate core≦12 μm, and
the composite particle is a cathode active material for the cathode.
6. The electrochemical device according to claim 5 , wherein the composite particle has a coverage (L′/L) of 0.2 or more, where:
L′ represents a length of the electronic conducting layer formed on a circumference of the particulate core, and
L represents a length of the circumference of the particulate core.
7. The electrochemical device according to claim 5 , wherein the composite particle has a BET specific surface area of from 1.5 m 2 /g to 15.0 m 2 /g.
8. The electrochemical device according to claim 5 , wherein the electron conducting layer has an average thickness of from 10 to 500 nm.