Lithium ion batteries comprising nanofibers

Abstract

Lithium ion batteries, electrodes, nanofibers, and methods for producing same are disclosed herein. Provided herein are batteries having (a) increased energy density; (b) decreased pulverization (structural disruption due to volume expansion during lithiation/de-lithiation processes); and/or (c) increased lifetime. In some embodiments described herein, using high throughput, water-based electrospinning process produces nanofibers of high energy capacity materials (e.g., ceramic) with nanostructures such as discrete crystal domains, mesopores, hollow cores, and the like; and such nanofibers providing reduced pulverization and increased charging rates when they are used in anodic or cathodic materials.

We claim: 
     
         1 - 91 . (canceled) 
     
     
         92 . A lithium-ion battery comprising an anode in a first chamber, a cathode in a second chamber, and a separator between the first chamber and the second chamber, and the separator comprising one or more polymer nanocomposite nanofiber(s) comprising a polymer matrix with ceramic and/or clay nanostructures embedded therein. 
     
     
         93 . The battery of  claim 92 , wherein the polymer is PE, UHMWPE, PP, PVA, PAN, PEO, PVP, PVDF, Nylon, aramid, PET, Polyimide, PMMA, or a combination thereof. 
     
     
         94 . The battery of  claim 92 , wherein the polymer nanocomposite comprises a ceramic, and the ceramic is silica, zirconia, or alumina. 
     
     
         95 . The battery of  claim 92 , wherein the polymer nanocomposite nanofiber comprises a clay, and the clay is bentonite, aluminum phyllosilicate, montmorillonite, kaolinite, illite, vermiculite, smectite, chlorite, silicate clay, sesquioxide clays, allophane, imogolite, fluorohectorate, laponite, bentonite, beidellite, hectorite, saponite, nontronite, sauconite, ledikite, magadiite, kenyaite, stevensite, or a combination thereof. 
     
     
         96 . The battery of  claim 92 , wherein the one or more polymer nanocomposite nanofiber(s) comprises on average 1-15 wt. % ceramic and clay. 
     
     
         97 . The battery of  claim 92 , wherein the separator has an average pore diameter of less than 1 micron. 
     
     
         98 . The battery of  claim 92 , wherein the separator has a peak pore diameter distribution of less than 1 micron. 
     
     
         99 . The battery of  claim 92 , wherein the separator has a thickness of 15-100 micron. 
     
     
         100 . The battery of  claim 92 , wherein the battery retains at least 70% of its discharge capacity (mAh/g) after 100 cycles at a charge rate of at least 250 mA per gram of separator. 
     
     
         101 . The battery of  claim 92 , wherein the one or more polymer nanocomposite nanofiber(s) has an average diameter of less than 1 micron, an average aspect ratio of at least 100, and an average specific surface area of at least 100 m 2 /g. 
     
     
         102 . The battery of  claim 92 , wherein the one or more polymer nanocomposite nanofiber(s) has an average length of at least 1000 microns. 
     
     
         103 . The battery of  claim 92 , wherein the cathode comprises one or more lithium-containing nanofiber comprising a matrix of a lithium material. 
     
     
         104 . The battery of  claim 103 , wherein the one or more lithium-containing nanofiber has an average diameter of less than 1 micron and an aspect ratio of at least 100. 
     
     
         105 . The battery of  claim 92 , wherein the anode comprises one or more anodic nanofiber, the anodic nanofiber comprising Si, Sn, Ge, or an oxide of Si, Sn, or Ge. 
     
     
         106 . The battery of  claim 105 , wherein the anodic nanofiber(s) comprises discrete domains comprising the Si, Sn, or Ge, or oxide Si, Sn, or Ge, the discrete domains being embedded in a carbon backbone. 
     
     
         107 . The battery of  claim 105 , wherein the one or more anodic nanofiber(s) comprise, on average, at least 50 wt % of Si, Sn, Ge, or an oxide of Si, Sn, or Ge. 
     
     
         108 . A lithium-ion battery comprising an anode in a first chamber, a cathode in a second chamber, and a separator between the first chamber and the second chamber, and the separator allowing ion transfer between the first chamber and second chamber in a temperature dependent manner,
 the separator comprising one or more polymer nanocomposite nanofiber comprising a polymer matrix with ceramic nanostructures embedded therein, the polymer being PE, UHMWPE, PP, PVA, PAN, PEO, PVP, PVDF, Nylon, aramid, PET, Polyimide, PMMA, or a combination thereof, and the ceramic being silica, zirconia, alumina, or a combination thereof;   the anode comprises one or more anodic nanofiber, the anodic nanofiber comprising Si, Sn, Ge, or an oxide of Si, Sn, or Ge; and   the cathode comprises one or more lithium-containing nanofiber comprising a matrix of a lithium material.   
     
     
         109 . A process for producing a battery separator, the process comprising gas assisted electrospinning a fluid stock to form a nanofiber mat, the fluid stock comprising (i) a plurality of nanoparticles, and (ii) a polymer, the separator comprising one or more nanofiber(s) comprising a continuous polymer matrix with non-aggregated nanoparticles embedded therein. 
     
     
         110 . The process of  claim 109 , further comprising annealing the nanofiber mat. 
     
     
         111 . The process of  claim 109 , further comprising compressing the nanofiber mat.