Method of activating two-dimensional materials for multivalent/polyatomic-ion intercalation battery electrodes

Abstract

A method for activating two-dimensional host materials for a multivalent/polyatomic ion battery may include adding a pillaring salt in electrolyte. This process may be followed by in-situ electrochemically intercalating the pillaring ions, solvent molecules and multivalent ions into the van der Waals gap of host materials. After the activation process, the host material is transformed into an interlayer-expanded 2D material with significantly enhanced specific capacity and rate performance for multivalent ion intercalation.

What is claimed is: 
     
         1 . A method for forming an intercalation electrode for an ion battery, the method comprising:
 adding a pillaring salt to an electrolyte, wherein the pillaring salt is chemically stable and soluble in the electrolyte and has a formula LX, where L is a cation and X is an anion, and L or X has a size suitable to expand layers of a host material to a desirable level;   positioning the host material in the pillaring salt and the electrolyte, wherein the host material is a two-dimensional, layered material selected from an elemental, metal, chalcogenide, metal oxide, oxy-halide, hydroxide, titanate, metal phosphate, or phosphonate; and   intercalating a pillaring ions of the pillaring salt into a van der Waals gap of the host material, wherein once expanded, an interlayer distance of the host material does not change during a charging stage and a discharging stage.   
     
     
         2 . The method of  claim 1 , wherein the pillaring ions of the pillaring salt is imidazolium, pyridinium, ferrocenium, alkyl-ammonium, pyrrolidinium, or piperridinium, and the anion is Cl − , TFSI − , BF 4   − , or AlCI x R 4-x   − . 
     
     
         3 . The method of  claim 1 , wherein the host material is the elemental, and the elemental is selected from graphite or black-phosphorous. 
     
     
         4 . The method of  claim 1 , wherein the host material is the metal, and the metal has a formula MX 2 , where M=Ti, Mo, V, W, Nb, Ta, Zr, or Hf and X═S or Se. 
     
     
         5 . The method of  claim 1 , wherein the host material is the chalcogenide, and the chalcogenide has a formula
 (MS) 1-x (TS 2 ) 2 , where 0≤x≤1, M=Sn, Pb, and T=Ti, Nb, or Ta;   MPX 3 , where M=Mg, V, Mn, Fe, Co, Ni, Zn, Cd, or In and X═S or Se; or   AMS 2 , where A=Li, Na, K, Rb, Cs, or Fr and M=Ti, V, Cr, Mn, Fe, Co, or Ni.   
     
     
         6 . The method of  claim 1 , wherein the host material is the metal oxide, and the metal oxides the metal oxides has a formula
 M x O y , where M=is a metal or a combination of metals that includes an alkali metal, and x and y are values determined by an oxidation state of M; or   MOXO 4 , where M=Ti, V, Cr, or Fe and X═P or As.   
     
     
         7 . The method of  claim 1 , wherein the host material is the oxy-halide, and the oxy-halide has a formula MOX, where M=Ti, V, Cr, or Fe and X═Cl or Br. 
     
     
         8 . The method of  claim 1 , wherein the host material is the hydroxide or the titanate. 
     
     
         9 . The method of  claim 1 , wherein the host material is the metal phosphate, and the metal phosphate has a formula M(HPO 4 ) 2 , where M=Ti, Zr, Ce, or Sn). 
     
     
         10 . The method of  claim 1 , wherein the host material is the phosphonate, and the phosphonate has the formula Zr(O 3 PR 2 ) 2 , where R═H, Ph, or Me. 
     
     
         11 . The method of  claim 1 , wherein the host material is expanded by the pillaring ions and solvent molecules in a first stage. 
     
     
         12 . The method of  claim 11 , wherein the host material is further expanded by the pillaring ions, the solvent molecules, and multivalent ions or polyatomic ions in a second stage. 
     
     
         13 . The method of  claim 12 , wherein the multivalent ions or the polyatomic ions are MgCl + , and the electrode is for a rechargeable magnesium battery. 
     
     
         14 . The method of  claim 12 , wherein the multivalent ions or the polyatomic ions comprise a multivalent metal. 
     
     
         15 . The method of  claim 12 , wherein the van der Waals gap of the host material is filled to a maximum with the pillaring ions, the solvent molecules, and multivalent ions or polyatomic ions in a third stage. 
     
     
         16 . The method of  claim 15  further comprising deintercalating the multivalent ions or polyatomic ions from the van der Waals gap during a charging process, wherein the interlayer distance of the host material does not change when deintercalating is complete. 
     
     
         17 . The method of  claim 1 , wherein the host material is electrochemically intercalated. 
     
     
         18 . The method of  claim 17 , wherein the host material utilized as a working electrode during electrochemical activation, a counter electrode is place in the pillaring salt and the electrolyte during the electrochemical activation, and a voltage differential is applied to the working electrode and the counter electrode during the electrochemical activation. 
     
     
         19 . An electrode for an ion battery comprising:
 a host material, wherein the host material is a two-dimensional, layered material selected from an elemental, metal, chalcogenide, metal oxide, oxy-halide, hydroxide, titanate, metal phosphate, or phosphonate; and   a pillaring ion, a solvent, and a multivalent ion or polyatomic ion intercalated into a van der Waals gap of the host material,
 wherein the pillaring ion is selected from a cation L or an anion X, where L or X has a size suitable to expand layers of the host material to a desirable level, 
 and the multivalent ion or polyatomic ion, 
   wherein further an interlayer spacing of the host material does not change during a charged stage and discharged stage.   
     
     
         20 . The electrode of  claim 19 , wherein the pillaring ion of the pillaring salt is imidazolium, pyridinium, ferrocenium, alkyl-ammonium, pyrrolidinium, or piperridinium, and the anion is Cl − , TFSI − , BF 4   − , or AlCI x R 4-x   − . 
     
     
         21 . The electrode of  claim 19 , wherein the host material is the elemental, and the elemental is selected from graphite or black-phosphorous. 
     
     
         22 . The electrode of  claim 19 , wherein the host material is the metal, and the metal has a formula MX 2 , where M=Ti, Mo, V, W, Nb, Ta, Zr, or Hf and X═S or Se. 
     
     
         23 . The electrode of  claim 19 , wherein the host material is the chalcogenide with a formula
 (MS) 1-x (TS 2 ) 2 , where 0≤x≤1, M=Sn, Pb, and T=Ti, Nb, Ta;   MPX 3 , where M=Mg, V, Mn, Fe, Co, Ni, Zn, Cd, or In and X═S or Se; or   AMS 2 , where A=Li, Na, K, Rb, Cs, or Fr and M=Ti, V, Cr, Mn, Fe, Co, or Ni.   
     
     
         24 . The method of  claim 19 , wherein the host material is the metal oxide with a formula
 M x O y , where M=is a metal or a combination of metals that includes an alkali metal, and x and y are values determined by an oxidation state of M; or   MOXO 4 , where M=Ti, V, Cr, or Fe and X═P or As.   
     
     
         25 . The electrode of  claim 19 , wherein the host material is the oxy-halide with a formula MOX, where M=Ti, V, Cr, or Fe and X═Cl or Br. 
     
     
         26 . The electrode of  claim 19 , wherein the host material is the hydroxide or the titanate. 
     
     
         27 . The electrode of  claim 19 , wherein the host material is the metal phosphate with a formula M(HPO 4 ) 2 , where M=Ti, Zr, Ce, or Sn). 
     
     
         28 . The electrode of  claim 19 , wherein the host material is the phosphonate with a formula Zr(O 3 PR 2 ) 2 , where R═H, Ph, or Me. 
     
     
         29 . The electrode of  claim 19 , wherein the van der Waals gap of the host material is filled to a maximum in the discharged stage, and the multivalent ion or polyatomic ion are deintercalated from the van der Waals gap in the charged stage. 
     
     
         30 . The electrode of  claim 19 , wherein the interlayer spacing of the host material relative to a pristine sample is 50% larger or more. 
     
     
         31 . The electrode of  claim 19 , wherein the electrode has a specific capacity of 120 mAh/g or greater. 
     
     
         32 . The electrode of  claim 19 , wherein the multivalent ion or the polyatomic ion is MgCl + , and the electrode is for a rechargeable magnesium battery. 
     
     
         33 . The electrode of  claim 19 , wherein the multivalent ions or the polyatomic ions comprise a multivalent metal.