Making lithium secondary battery electrodes using an atmospheric plasma

A method of forming an electrode member of a lithium-ion electrochemical cell, the method comprising:

• adding solid particles of lithium-ion cell electrode material to a flowing gas stream, the solid particles consisting essentially of particles of a lithium-ion cell electrode material combined with an electrically conductive metal, the solid particles being dispersed and carried in the flowing gas stream;
• generating an atmospheric plasma in the gas stream to heat the solid particles by the plasma and to at least partially melt the electrically conductive metal;
• and
• directing the plasma stream and heated solid particles against a metal current collector substrate layer, while moving at least one of the directed plasma and the current collector substrate layer with respect to the other, to deposit the plasma-heated solid particles in a sheet layer of predetermined thickness and porosity on a selected surface area of the metal current collector substrate layer, the conductive metal re-solidifying to bond the solid particles to each other and to the metal current collector substrate layer, the bonded solid particles forming a layer of lithium-ion cell electrode material on the metal current collector substrate, the lithium-ion electrode material having a thickness up to about two hundred micrometers.

A method of forming an electrode member of a lithium-ion electrochemical cell, the method comprising:

• adding solid particles of copper or aluminum to a flowing gas stream, the solid particles being dispersed and carried in the flowing gas stream;
• generating an atmospheric plasma in the gas stream, the plasma heating the solid particles and at least partially melting the copper or aluminum particles;
• directing the plasma against a selected surface area of a separator membrane substrate layer, while moving the plasma relative to the selected surface area of the separator membrane, to deposit the plasma-heated copper or aluminum particles in a layer on a selected surface area of the separator membrane substrate layer, the copper or aluminum particles re-solidifying to bond to each other and to the separator membrane substrate layer, the bonded copper or aluminum particles forming a current collector layer of on the selected surface area of the separator membrane substrate and having a thickness up to about twenty micrometers;
• assembling the separator membrane, with its current collector layer, into a lithium-ion electrochemical cell;
• operating the assembled lithium-ion cell to transfer lithium from an electrode member of the cell and to deposit the lithium as a layer of reference electrode material on the surface of the plasma-deposited, copper or aluminum current collector layer;
• and, thereafter
• operating the lithium-ion cell using the reference electrode material to assess the function of electrode members of the cell.

A method of forming the anode member of a lithiated silicon-sodium electrochemical cell, the formed electrode member comprising a bonded sheet layer, the method comprising:

• adding solid particles of lithiated silicon-sulfur cell anode material to a flowing gas stream, the solid particles consisting essentially of (i) particles of an electrically conductive metal or of (ii) particles of cell anode material combined with an amount of electrically conductive metal for bonding of the particles of anode material, the solid particles being dispersed and carried in the flowing gas stream;
• generating an atmospheric plasma in the gas stream to heat the solid particles by the plasma and to at least partially melt the electrically conductive metal;
• and
• directing the atmospheric plasma, containing the heated solid particles, against a selected surface of a substrate, while moving at least one of the directed plasma and the selected surface of the substrate with respect to the other, to deposit the plasma-heated solid particles in a sheet layer of predetermined thickness and porosity on the selected surface area of the substrate, the conductive metal re-solidifying to bond the solid particles to each other in the sheet layer and to bond the sheet layer to the substrate;
• the substrate being a sheet layer portion of an anode of a lithiated silicon-sulfur electrochemical cell or a separator membrane member of a lithiated silicon-sulfur electrochemical cell, the final sheet thickness of deposited plasma-heated solid particles on the selected area of the substrate being up to about two hundred micrometers and comprising one or more sheet layers of such deposited plasma-heated solid particles.