Lithiation of porous-Si for high performance anode
AssigneeDevendra K Sadana
InventorsDevendra K Sadana, Joel P. de Souza, Brian Williams, Francis Christopher Farmer
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Abstract
An element to be used as an anode in a lithium-ion battery comprising a lithiated single crystal porous-silicon layer made on the surface of a p-doped single crystal Si of thickness 25-1000 mm and resistivity of less than 0.01-ohm cm. Successful lithiation is achieved either electrochemically or by direct alloying of lithium metal with the porous-Si with a wide range of porosities. The lithiated silicon anode allows a high cathode loading in a lithium-ion battery resulting in record current densities without the formation of lithium dendrites.
Claims15
An electrochemically lithiated single crystal porous-Si/p-Si alloyed anode comprising:
- a first layer which is a solid electrolyte interphase (SEI) layer comprising a composition having a plurality of lithium compounds selected from Li3CO3, LiF, and Li2O, said layer having a thickness of between about 20 nm to 20 μm, said first layer being positioned atop a second layer;
- said second layer comprises an Li—Si alloy mixture of electro-deposited Li and porous Si having a porosity of between about 30% and 75%, and a portion of a reacted p-Si immediately underneath said porous-Si, having an overall thickness of between about 10 μm and 50 μm;
- said second layer being situated atop a p-doped Si layer substrate that has a layer thickness of between about 5 μm and 1000 μm;
- said p-doped Si layer is doped with Boron (B), has concentrations in excess of 5×1018 cm−3, has a resistivity value of <0.01 ohm·cm, and a thickness of between about 10 μm and 1000 μm.
Dependencies are inferred from the claim text.