Method of producing protected anode active material particles for rechargeable lithium batteries

A method of producing multiple particulates, said method comprising:

• A) Dispersing multiple primary particles of an anode active material, having a particle size from 5 nm to 20 μm, and a reactive mass comprising a blowing agent and a polymer, reactive oligomer, or monomer and initiator in a liquid medium to form a reactive slurry, wherein said slurry further contains a reinforcement material containing graphite fibers, glass fibers, ceramic fibers, metal filaments or metal nano-wires, whiskers, or a combination thereof, and/or a lithium ion-conducting additive dispersed therein;
• B) Shaping said reactive slurry and optionally removing said liquid medium to form reactive micro-droplets;
• C) Polymerizing or curing the reactive micro-droplets and activating the blowing agent to produce said multiple particulates having a diameter from 100 nm to 50 μm;
• wherein at least one of the multiple particulates comprises a polymer foam material having pores and a single or a plurality of primary particles of said anode active material embedded in or in contact with said polymer foam material, wherein said primary particles of anode active material have a total solid volume Va, and said pores have a total pore volume Vp, and the volume ratio Vp/Va is from 0.1/1.0 to 10/1, wherein the polymer foam material is selected from ethylene-vinyl acetate (EVA) foam, a copolymer of ethylene and vinyl acetate (polyethylene-vinyl acetate, PEVA), a polyethylene foam (e.g. low-density poly ethylene, LDPE foam), polyimide foam, polypropylene (PP) foam, polystyrene (PS) foam (including expanded polystyrene, expanded high-impact polystyrene), polyvinyl chloride (PVC) foam;
• polymethacrylimide (PMI) foam, or a combination thereof;
• and
• D) incorporating said multiple particulates into a battery anode electrode.

A method of producing multiple particulates, said method comprising:

• A) Dispersing multiple primary particles of an anode active material, having a particle size from 5 nm to 20 μm, and a reactive mass comprising a blowing agent and a polymer, reactive oligomer, or monomer and initiator in a liquid medium to form a reactive slurry;
• B) Shaping said reactive slurry and optionally removing said liquid medium to form reactive micro-droplets;
• C) Polymerizing or curing the reactive micro-droplets and activating the blowing agent to produce said multiple particulates having a diameter from 100 nm to 50 μm;
• wherein at least one of the multiple particulates comprises a polymer foam material having pores and a single or a plurality of primary particles of said anode active material embedded in or in contact with said polymer foam material, wherein said primary particles of anode active material have a total solid volume Va, and said pores have a total pore volume Vp, and the volume ratio Vp/Va is from 0.1/1.0 to 10/1, wherein said step (B) includes operating a procedure selected from pan-coating, air-suspension coating, centrifugal extrusion, vibration-nozzle encapsulation, coacervation-phase separation, interfacial polycondensation and interfacial cross-linking, matrix polymerization, extrusion and pelletizing, or a combination thereof, wherein the polymer foam material is selected from ethylene-vinyl acetate (EVA) foam, a copolymer of ethylene and vinyl acetate (polyethylene-vinyl acetate, PEVA), a polyethylene foam (e.g. low-density poly ethylene, LDPE foam), polyimide foam, polypropylene (PP) foam, polystyrene (PS) foam (including expanded polystyrene, expanded high-impact polystyrene), polyvinyl chloride (PVC) foam;
• polymethacrylimide (PMI) foam, or a combination thereof;
• and
• D) incorporating said multiple particulates into a battery anode electrode.