Electrode comprising protective layer for lithium ion secondary battery and lithium ion secondary battery
A lithium ion secondary battery containing a pair of electrodes facing each other, and a separator interposed between the electrodes, wherein at least one of the electrodes has a protecting layer, an active-material containing layer, and a collector sequentially from the separator. The protecting layer contains a silicone resin particle having at least one structural unit represented by RSiO 1.5 and R 2 SiO, where R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.
1. A lithium ion secondary battery comprising
a pair of electrodes facing each other; and
a separator interposed between the electrodes,
wherein:
at least one of the electrodes has a protecting layer, an active-material containing layer, and a collector sequentially from the separator;
the protecting layer contains a silicone resin particle having at least one structural unit represented by RSiO 1.5 and R 2 SiO; and
R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group.
2. The lithium ion secondary battery according to claim 1 , wherein the silicone resin particle has an average particle size of 0.3 to 6.0 μm.
3. The lithium ion secondary battery according to claim 1 , wherein the protecting layer has a thickness of 0.3 to 6.0 μm.
4. The lithium ion secondary battery according to claim 1 , wherein an aspect ratio, which is a ratio of a major-axis length relative to a minor-axis length of the silicone resin particle is from 1.00 to 1.50.
5. The lithium ion secondary battery according to claim 1 , wherein the silicone resin particle is a polymethylsilsesquioxane particle.