Electrode plate for battery and lithium secondary battery including the same
An electrode plate for a battery includes a current collector having a substrate and a plurality of protrusions that are carried on the substrate; and an active material layer that is carried on the current collector. The protrusions include a conductive material that undergoes plastic deformation more easily than the substrate. A lithium secondary battery includes the above electrode plate.
1. An electrode plate for a battery comprising:
a current collector including a substrate and a plurality of protrusions that are carried on said substrate; and
an active material layer that is carried on said current collector;
wherein said substrate is a copper alloy foil containing at least one element selected from the group consisting of Ni, Si, Sn, Be, Co, Ti, Fe and Zr,
said protrusions comprise a conductive material that undergoes plastic deformation more easily than said substrate, and
said active material layer comprises columnar particles of a silicon-containing material in which said columnar particles are carried on said protrusions.
2. The electrode plate for a battery in accordance with claim 1 , wherein said protrusions have a height of 1 to 15 .mu.m.
3. The electrode plate for a battery in accordance with claim 1 , wherein said protrusions comprise copper having a purity of not less than 99.9 wt %.
4. The electrode plate for a battery in accordance with claim 1 , wherein at least part of said columnar particles is inclined with respect to a normal line direction of the surface of said current collector.
5. The electrode plate for a battery in accordance with claim 4 , wherein said columnar particles each is a laminate of a plurality of sub-particle layers.
6. The electrode plate for a battery in accordance with claim 5 , wherein the growth directions of said plurality of sub-particle layers are inclined with respect to the normal line direction of the surface of said current collector.
7. The electrode plate for a battery in accordance with claim 6 , wherein the growth directions of said plurality of sub-particle layers are inclined alternately in a first direction and a second direction with respect to the normal line direction of the surface of said current collector.
8. The electrode plate for a battery in accordance with claim 1 , wherein said protrusions are formed by a plating method, vapor deposition method, sputtering method or sintering method.
9. A lithium secondary battery comprising a positive electrode capable of absorbing and desorbing lithium ions, the electrode plate in accordance with claim 1 serving as a negative electrode, a separator that is disposed between said positive electrode and said negative electrode, and an electrolyte having lithium ion conductivity.