Non-aqueous electrolyte secondary cell
AssigneeSony Corporation
InventorsAkira Yamaguchi, Atsuo Omaru, Masayuki Nagamine
Life of this patent
Estimating the term…
Abstract
A non-aqueous electrolyte secondary cell which achieves satisfactory low temperature characteristics and high safety against overcharging in combination. The cell includes a lithium-containing cathode, an anode capable of doping and undoping lithium, a non-aqueous electrolyte and a separator. The separator is made up by a plurality of layers of a porous material or materials presenting micro-sized pores. The layers of the porous material or materials is formed of micro-porous separator materials representing different combinations of the porosity, melting point or material/compositions.
Claims16
1-19. (canceled)
A non-aqueous electrolyte secondary cell comprising;
- a cathode comprising a lithium-containing cathode active material,
- an anode comprising an anode active material capable of doping and undoping lithium,
- a non-aqueous electrolyte, and
- a separator comprising a plurality of layers of a microporous material;
- wherein at least two microporous material layers have different porosity values, such layers including a highest porosity layer and a lowest porosity layer;
- the highest porosity layer has a larger average pore diameter than the lowest porosity layer;
- the lowest porosity layer has a porosity value of A;
- the highest porosity layer has a porosity value of B;
- and a porosity ratio A/B is 44% to 93%.
A non-aqueous electrolyte secondary cell comprising;
- a cathode comprising a lithium-containing cathode active material,
- an anode comprising an anode active material capable of doping and undoping lithium,
- a nonaqueous electrolyte, and
- a separator comprising at least two layers of a microporous polyolefine material, such layers including a lowest porosity layer proximate to the cathode and a highest porosity layer proximate to the anode;
- wherein the lowest porosity layer has a thickness of 2% to 55% of the separator thickness, an average pore diameter of 0.03 μm to 0.2 μm, and a porosity value A of 20% to 40%;
- the highest porosity layer has a thickness of 20% to 85% of the separator thickness, an average pore diameter of 0.1 μm to 1.0 μm, and a porosity value B of 45% to 60%;
- and a porosity ratio of A/B is between 44% and 93%.
Dependencies are inferred from the claim text.