6.5 Lithium-Sulfur Battery
179
Table 6.8 Electrochemical performances of porous carbon materials with different textual
parameters/sulfur composites
Material
Pore
size
(nm)
Pore
volume
(cm 3 /g)
BET
total
surface
area
(m 2 /g)
Sulfur
content
Current
density
(mA/g)
1st
discharge
capacity
(mAh/g)
Cycling
capacity
(mAh/g)
LMC/S
123
9.0
1215
70%
300
1380
30th, 800
100th,
615
CMK-3/S
3.3
2.1
1976
70%
168
1005
20th, 800
MPC/S
7.3
0.503
1566
11.7%
2500
1584
30th, 805
MPC/S
10–30 –
381
25%
50
1300
40th, 600
Active
carbon/sulfur
1.76
–
1486
70%
100
1181
60th, 720
Carbon
xerogel/sulfur
–
–
1774
<60%
220
1311
30th, 800
Elemental
sulfur
–
–
–
300
1050
30th, 600
The capacity values are calculated according to the elemental sulfur
structure can well absorb the electrolyte, which inhibits the dissolution of lithium
polysulfide to some extent. People use hollow-structured carbon fibers or carbon
nanotubes to further improve their properties.
6.5.4.4 Sulfur/Conductive Polymer Composites
In the past 20 years, conductive polymers have developed greatly in terms of synthesis
technology and performance enhancement, which is continuously applied to lithiumsulfur batteries.
Sulfur polymer composite mainly in two forms: one is to form a “polymer coated
sulfur” core–shell structure, such as polypyrrole/sulfur (PPY/S), polyaniline/sulfur
(PANi/S), poly (3,4-ethylene dioxythiophene) (PEDOT/S), polythiophene/sulfur
(PTh/S) and other composite materials (Fig. 6.21) (Wu et al. 2011). The structure
design of the hollow nano-sulfur covered by the conductive polymer effectively
solved the problem of structural destruction attributed to the volume changing of
sulfur in the charging and discharging process, and obtained excellent cycle performance. The other is a “sulfur-coated polymer” core–shell structure, such as the
fusion of sulfur to the surface of a conductive polymer matrix by means of melting
or chemical deposition (Fig. 6.22) (Fu and Manthiram 2012). Such conductive polymers mainly include PPY nanowires, nanotubes, and other network structures, PANi
179
Table 6.8 Electrochemical performances of porous carbon materials with different textual
parameters/sulfur composites
Material
Pore
size
(nm)
Pore
volume
(cm 3 /g)
BET
total
surface
area
(m 2 /g)
Sulfur
content
Current
density
(mA/g)
1st
discharge
capacity
(mAh/g)
Cycling
capacity
(mAh/g)
LMC/S
123
9.0
1215
70%
300
1380
30th, 800
100th,
615
CMK-3/S
3.3
2.1
1976
70%
168
1005
20th, 800
MPC/S
7.3
0.503
1566
11.7%
2500
1584
30th, 805
MPC/S
10–30 –
381
25%
50
1300
40th, 600
Active
carbon/sulfur
1.76
–
1486
70%
100
1181
60th, 720
Carbon
xerogel/sulfur
–
–
1774
<60%
220
1311
30th, 800
Elemental
sulfur
–
–
–
300
1050
30th, 600
The capacity values are calculated according to the elemental sulfur
structure can well absorb the electrolyte, which inhibits the dissolution of lithium
polysulfide to some extent. People use hollow-structured carbon fibers or carbon
nanotubes to further improve their properties.
6.5.4.4 Sulfur/Conductive Polymer Composites
In the past 20 years, conductive polymers have developed greatly in terms of synthesis
technology and performance enhancement, which is continuously applied to lithiumsulfur batteries.
Sulfur polymer composite mainly in two forms: one is to form a “polymer coated
sulfur” core–shell structure, such as polypyrrole/sulfur (PPY/S), polyaniline/sulfur
(PANi/S), poly (3,4-ethylene dioxythiophene) (PEDOT/S), polythiophene/sulfur
(PTh/S) and other composite materials (Fig. 6.21) (Wu et al. 2011). The structure
design of the hollow nano-sulfur covered by the conductive polymer effectively
solved the problem of structural destruction attributed to the volume changing of
sulfur in the charging and discharging process, and obtained excellent cycle performance. The other is a “sulfur-coated polymer” core–shell structure, such as the
fusion of sulfur to the surface of a conductive polymer matrix by means of melting
or chemical deposition (Fig. 6.22) (Fu and Manthiram 2012). Such conductive polymers mainly include PPY nanowires, nanotubes, and other network structures, PANi