SULFUR-INFUSED CARBON FOR SECONDARY BATTERY MATERIALS
In one aspect, a method of producing a sulfur-infused carbonaceous material as a cathode material for use in a Li—S battery is described, including providing a carbonaceous material; mixing elemental sulfur with the carbonaceous material; and heating the mixed sulfur and the carbonaceous material at a temperature from about 445° C. to about 1000° C. for a period of time and under a pressure greater than 1 atm to generate a sulfur vapor to infuse the carbonaceous material to result in a sulfur-infused carbonaceous material. In another aspect, a reactor for producing a sulfur-infused carbonaceous material as a cathode material for use in a Li—S battery is described, including a reactor body capable of withstanding a pressure from about 1 atm to about 150 atm; and an inner sulfur-resistant layer at the inner surface of the reactor, wherein the inner layer is inert to sulfur vapor at a temperature from about 450° C. to about 1000° C.
1 . A method of producing a sulfur-infused carbonaceous material as a cathode material for use in a Li—S battery, comprising:
providing a carbonaceous material;
mixing elemental sulfur with the carbonaceous material; and
heating the mixed sulfur and the carbonaceous material at a temperature from about 445° C. to about 1000° C. for a period of time and under a pressure greater than 1 atm to generate a sulfur vapor to infuse the carbonaceous material with sulfur to result in a sulfur-infused carbonaceous material.
2 . The method of claim 1 , wherein the sulfur-infused carbonaceous material comprises from about 10 wt % to about 99 wt % of sulfur after a single heating operation.
3 . The method of claim 1 , wherein the sulfur-infused carbonaceous material comprises more than 50 wt % of sulfur after a single heating operation.
4 . The method of claim 1 , wherein the sulfur-infused carbon comprises more than 60 wt % sulfur after a single heating operation.
5 . The method of claim 1 , wherein the method further comprises cooling the heated mixed sulfur and the carbonaceous material.
6 . The method of claim 1 , wherein the period is about 1 minute to about 4 hours.
7 . The method of claim 1 , wherein the carbonaceous material is selected from the group consisting of coal, polyacrylonitrile, resorcinol-formaldehyde resins, KetJen, aerogel, coconut, bamboo, plant derived carbon, CNT, graphene, acetylene black, Super P and a combination thereof.
8 . The method of claim 1 , wherein providing a carbonaceous material further comprises activating the carbonaceous material.
9 . The method of claim 8 , wherein activating the carbonaceous material comprises using a base selected from the group consisting of KOH, NaOH, LiOH, and combinations thereof.
10 . The method of claim 9 , wherein the activated carbonaceous material has a surface area greater than about 1000 m 2 /g.
11 . The method of claim 1 , wherein the temperature is from 500° C. to about 800° C.
12 . The method of claim 1 , wherein the temperature is from 500° C. to about 600° C.
13 . The method of claim 1 , wherein the pressure is between about 2 atm to about 150 atm.
14 . The method of claim 1 , wherein the temperature is about 500° C. to about 600° C. and the pressure is about 2 atm to 3 atm.
15 . The method of claim 1 , wherein the temperature is about 700° C. to about 800° C. and the pressure is about 20 atm to 30 atm.
16 . The method of claim 1 , wherein the temperature is about 1000° C. and the pressure is about 140 atm to 150 atm.
17 . The method claim 1 , wherein providing a carbonaceous material comprises providing an activated coal.
18 . The method of claim 17 , wherein the activated coal has a heavy metal ion impurity of less than 100 ppm and a surface area greater than 1000 m 2 /g;
19 . The method of claim 18 , wherein providing an activated coal comprises:
purifying coal to contain less than 100 ppm of heavy ion impurities;
activating coal by heating a mixture of the purified coal and a base; and
sintering the activated coal at a temperature in the range of 900° C.-1300° C. to provide an activated coal having a surface area greater than 1000 m 2 /g.
20 . The method of claim 19 wherein purification comprises:
treating coal with leaching solution containing acids, oxidizers, and water; and
washing the coal with water to remove impurities.
21 . The method of claim 17 , wherein the activation step comprises heating to temperatures between 500 and 900° C.
22 . The method of claim 17 , further comprising pulverizing the coal.
23 . The method of claim 22 further comprising heating to a temperature of 900° C. for 8 to 10 hours prior to pulverizing.
24 . The method of claim 19 , wherein purifying coal comprises using an acid selected from the group consisting of HCl, H 2 SO 4 , HNO 3 , and combinations thereof.
25 . The method of claim 19 , wherein activating coal comprises using a base selected from the group consisting of KOH, NaOH, LiOH, and combinations thereof.
26 . The method of claim 19 , wherein sintering comprises using a gas environment selected from the group consisting of N 2 , CO 2 , Ar, He, H 2 , CO, NO x , and combinations thereof.
27 . The method of claim 19 , comprising providing activated coal having a surface area between 1000 and 2000 m 2 /g.
28 . The method of claim 1 , wherein providing a carbonaceous material comprises providing activated carbonaceous material having graphitic content between 1 and 20 mass %.
29 . The method of claim 1 , wherein providing a carbonaceous material comprises providing activated carbonaceous material having graphitic content between 5 and 10 mass %.
30 . The method of claim 1 , wherein the sulfur-infused carbon comprises between 60 wt % and 95 wt % sulfur after in a single heating operation.
31 . A Li—S battery, comprising:
a cathode comprising a coal-sulfur composite, the composite comprising activated coal having a heavy metal ion impurity of less than 100 ppm, a surface area greater than 1000 m 2 /g and at least 60 wt % sulfur;
an electrolyte; and
a lithium anode.
32 . The battery of claim 31 , wherein the electrolyte comprises a thermally stable ionic liquid, lithium salt, and aprotic solvent.
33 . The battery of claim 31 comprising activated coal having a surface area between 1000 and 2000 m 2 /g.
34 . The battery of any of claims 31 , comprising activated coal having graphitic content between 1 and 20 mass %.
35 . The battery of any of claims 34 comprising activated coal having graphitic content between 5 and 10 mass %.
36 . The battery of any one of claims 31 , wherein initial battery capacity is between 400 and 1200 mAh/g.
37 . The battery of any one of claims 36 , wherein initial battery capacity is between 700 and 1000 mAh/g.
38 . A reactor for producing a sulfur-infused carbonaceous material as a cathode material for use in a Li—S battery, comprising:
a reactor body configured to withstand a pressure from about 1 atm to about 150 atm; and
an inner sulfur-resistant layer at the inner surface of the reactor body, wherein the inner layer is inert to sulfur vapor at a temperature from about 450° C. to about 1000° C.
39 . The reactor of claim 38 , wherein the reactor body and the inner layer are made of the same material.
40 . The reactor of claim 39 , wherein the material withstands a pressure from about 1 atm to about 150 atm and is layer is inert to sulfur vapor at a temperature from about 450° C. to about 1000° C.
41 . The reactor of claim 39 , wherein the material is selected from the group consisting of titanium, molybdenum, Tungsten and a combination thereof.
42 . The reactor of claim 38 , wherein the reactor body and the inner layer are made of different materials.
43 . The reactor of claim 42 , wherein the reactor body is made of a material selected from the groups consisting of titanium, molybdenum, Tungsten, stainless steel, and a combination thereof.
44 . The reactor of claim 42 , wherein the inner layer is made of a material selected from the group consisting of titanium, molybdenum, Tungsten, quartz, alumina, silicon carbide, Nucerite 7040 (Pfaudler), Nitraglass 6510 (Pfaudler), SiO 2 , and a combination thereof.
45 . The reactor of claim 42 , wherein the inner layer is a sheath or liner configured to slide in and out of the reactor body.
46 . The reactor of claim 42 , wherein the inner layer is a coating coated on the inner surface of the reactor body.