文章编号:1007-8827(2014)04-0309-07
石墨烯包覆炭硫复合物正极材料的制备及其电化学性能
李芳菲1,2,吕伟1,牛树章1,2,李宝华1
(1.清华大学深圳研究生院下一代动力与储能电池和炭功能材料工程实验室,广东深圳518055;
2.清华大学材料学院先进材料教育部重点实验室,北京100084)
摘要:利用石墨烯作为新型的阻挡层,设计并制备出具有核壳结构的石墨烯包覆多孔炭/硫复合材料,抑制锂硫电池中的 穿梭效应 ,以提高正极材料的循环性能三该结构利用多孔炭材料作为储存硫的载体,而石墨烯作为阻挡层可以限制充放电过程中形成的多硫化物向体相电解液中的扩散,从而实现对正极材料的容量和循环性能的提高三此外,提出一种简便的组装方法来实现石墨烯在多孔炭/硫复合材料表面的包覆三利用氧化石墨烯在液相还原过程中官能团的去除来降低亲水性,从而使其自发地包覆在不亲水的多孔炭/硫复合材料表面,形成石墨烯包覆的核壳结构三
关键词:锂硫电池;核壳结构;还原氧化石墨烯;炭硫复合
中图分类号:TB332文献标识码:A
收稿日期:2014-06-15;修回日期:2014-08-11
基金项目:国家重点基础研究发展计划(2014CB932400);国家自然科学基金(51202121,51232005);NSAF联合基金(U1330123);深圳市科技计划项目(JC201005310705A,JCYJ20120619152808478,JCYJ20130402145002382);广东省创新研发团队计划(2009010025).
通讯作者:李宝华,副研究员.E-mail:libh@https://www.doczj.com/doc/a519076134.html,
作者简介:李芳菲,硕士研究生,E-mail:lbj19561109@https://www.doczj.com/doc/a519076134.html,
Preparation and electrochemical performance
of a graphene-wrapped carbon/sulphur composite cathode
LI Fang-fei1,2,LU Wei1,NIU Shu-zhang1,2,LI Bao-hua1
(1.Engineering Laboratory for Next Generation Power and Energy Storage Batteries,
Engineering Laboratory for Functionalized Carbon Materials,Graduate School at Shenzhen,Tsinghua University,Shenzhen518055,China;
https://www.doczj.com/doc/a519076134.html,boratory of Advanced Materials,School of Materials,Tsinghua University,Beijing100084,China)
Abstract:Graphene is used as a barrier film to suppress the shuttle effect and to improve the performance of activated carbon-sulphur hybrid cathode materials in a lithium-sulphur battery by forming a core-shell structure.Graphene wraps around the activated carbon-sulphur hybrid to form a core-shell structure,in which the porous carbon framework stores most of the sulphur and the gra-phene layer suppresses the movement of the soluble polysulfide in the electrolyte during charge-discharge,resulting in an improve-ment of capacity and cyclic stability during long-term cycling.Such a core-shell structure is formed by changing the hydrophilicity of graphene oxide during reduction,in which the hydrophobic graphene closely wraps around the hydrophobic carbon surface. Keywords: Lithium-sulphurbattery;Core-shell structure;Reduced graphene oxide;Carbon-sulphur compound Foundation item:National Key Basic Research Program of China(2014CB932400);National Natural Science Foundation of China (51202121,51232005);NSAF(U1330123);Shenzhen Technical Plan Project(JC201005310705A,
JCYJ20120619152808478,JCYJ20130402145002382);Guangdong Province Innovation R&D Team Plan for En-
ergy and Environmental Materials(2009010025).
Corresponding author:LI Bao-hua,Associate Professor.E-mail:libh@https://www.doczj.com/doc/a519076134.html,
Author introduction:LI Fang-fei,Master candidate.E-mail:lbj19561109@https://www.doczj.com/doc/a519076134.html,
English edition available online ScienceDirect(https://www.doczj.com/doc/a519076134.html,/science/journal/18725805).
DOI:10.1016/S1872-5805(14)60140-2
1 Introduction
In recent years,enormous effort has been made to develop batteries with a higher capacity and energy density to meet the requirement for all-electric vehi-cles and green energy storage[1].Lithium-sulphur battery,newly emerged a few decades ago,occurs to people with its super high discharge capacity (1675mAh/g)and theoretical energy density
第29卷第4期
2014年8月新型炭材料
NEW CARBON MATERIALS Vol.29 No.4 Aug.2014
(2600Wh/kg)[2].Moreover,low cost and environ-mental-friendly sulphur electrode makes it promising in above applications[2-4].However,its practical ap-plication is hindered by the inherent nature of sulphur cathode.For example,octasulphur(cyclo-S8),the most stable allotrope of sulphur at room temperature, undergoes a series ofstructural and morphological changes during the charge-discharge process involving the formation of soluble lithium polysulfide Li2Sx (3?x?8)and insoluble Li2S2and Li2S.Soluble lithium polysulfide comes back and forth in electrolyte between electrodes during the charge-discharge process,accompanied with reduction and oxidation reaction,which is called shuttle effect [5-8],resul-ting in a loss of active material and spoiling of elec-trolyte,and thus leading to a poor cyclic performance and a low Coulombic efficiency.
In order to solve this problem,carbon materials, polymers and metal oxides framework are studied to store sulphur and limit dissolution of polysulfide in the electrolyte through both physical and chemical interac-tions[9-12].Among them,carbon framework is be-lieved to be more promising,and various carbons (such as porous carbon,carbon nanotube,graphene, carbon fiber)have been frequently studied[13-29].Car-bon matrix not only provides room to hold sulphur and restrict the shuttle of polysulfide,but also im-proves the electrical conductivity of sulphur cathode. However,the suppression of dissolution of polysul-fide and loss of active materials are unsatisfactory yet by using the simplex carbon structure.Thus,it is ur-gent to design a hybrid structure to improve it.
Herein,we proposed a hybrid structure to sup-press the shuttle effect and improve the cyclic abili-ty of the sulphur cathode.We used the activated car-bon as the vessel to store the sulphur,and then,a graphene layer was coated on the activated carbon/ sulphur hybrid(CS)as a barrier film forming a core-shell structure by a self-assembly method.Thus,the porous structure and such barrier layer conspire against the shuttle of polysulfide from the electrode, resulting in the improvement of capacity and cyclic performance.We also proposed a self-assembly ap-proach that was made possible by the hydrophilicity change of graphene oxide(GO)by reduction.This hybrid achieves a proper loading of sulphur(43% mass fraction)and gives a stable electrochemical per-formance with an increasing discharge capacity of 300-400mAh/g,compared to CS hybrid with a42% sulphur loading.Also,an excellent rate capability is achieved.The improved electrochemical performance of this hybrid is attributed to the dual functions of the activated carbon and graphene as mentioned above.2 Experimental
2.1 Sample preparation
In a typical experiment,activated carbon(XPF-01,Nanjing XF-NANO)and sulphur underwent a thermal treatment at150?for8h under argon condi-tion to enable sulphur melt into the pores,and then heated at300?for2h to make the sulphur on exter-nal surface sublime to obtain CS hybrid.Proper amount of such hybrid was added into GO dispersion with a concentration of2mg/mL under strong sonica-tion to form a uniform mixture since GO can be used as a new type of dispersant.Then,suitable amount reduction agent(N2H4四H2O)was added in the above mixture,and GO was reduced into reduced graphene oxide(RGO)accompanied with the loss of oxygen-functional groups,resulting in a loss of hydrophilici-ty.Thus,the graphene layer certainly wrapped on the hydrophobic CS surface to obtain the core-shell struc-ture as shown in Fig.1.After centrifugation,filtration and drying,such product was produced and denoted as RGO@CS.
Fig.1 Schematic process of the preparation of RGO@C. 2.2 Structure characterization
Scanning electron microscopic(SEM)observa-tions were conducted with Hitachi S-4800(Hitachi, Japan).Transmission electron microscopic(TEM) observations were performed using JEM-2100F(JE-OL,Japan)equipped with EDX which was used for elemental analysis.The X-ray diffraction(XRD) patterns were collected at room temperature using the reflection mode(D8FOCUS,Cu Kαradiation,λ= 0.154nm).Nitrogen adsorption was measured by using a BEL mini-instrument,and the specific surface area was obtained by Brunauer-Emmett-Teller(BET) analyses of the adsorption isotherm.Raman spectra were recorded by a micro-Raman spectroscope(JY HR800)using532.05nm incident radiation and a50?aperture.Thermogravimetric analysis(Rigaku,Ja-pan)measurements were performed to calculate the sulphur content in the hybrid.
2.3 Electrochemical measurements
The RGO@CS hybrid powder was mixed with polyvinyldifluoride(PVDF)and super P carbon black
四013四新型炭材料第29卷
in a weight ratio of8?1?1in N-Methyl-2-pyrrolidone (NMP)solvent to form a slurry.The slurry then was coated on an Al foil and dried under vacuum at60?for24h.The foil was then cut to a circular pellet with a diameter of15mm used as cathode.The electrolyte was1.0mol/L LTFSI dissolved in DOL?DME(1?1 in volume).A2032coin cell was used to assemble the test cell in an Ar-filled glovebox(MBraun).Cy-clic voltammetry(CV)was measured at a scan rate of0.1mV/s within a potential range of1.5-3.0V (vs.Li+/Li).LAND galvanostatic charge/discharge instrument was used to test the rate performance. 3 Results and discussion
To characterize the morphology of RGO@CS, SEM and TEM are used.From the SEM image of RGO@CS shown in Fig.2,we can clearly observe the graphene layer almost fully wrapped on the CS surface,resulting in a coarse surface.In comparison, the CS hybrid shows a very flat surface(Fig.2a). Such layer prevents polysulfide and sulphur from dis-solving into bulk electrolyte and improving the cyclic stability.Moreover,Fig.2b also shows that some pores exist on the graphene layer,which can provide ion transportation channels,ensuring the power per-formance of the RGO@CS with a core-shell struc-ture.
TEM images also prove the successful wrapping of RGO on the CS surface.The thin RGO layer with a winkled structure can be clearly and easily identified from the TEM images shown in Fig.3a and3b to be wrapped on the CS hybrid.The element mapping shown in Fig.3c and3d show the elemental distribu-tions of carbon and sulphur in RGO@CS,respective-ly.It can be seen that the sulphur is mostly stored in the activated carbon and distributes uniformly.The TEM characterizations also show the RGO layer on the CS surface is very thin and very little sulphur ex-ists on the graphene surface.SEM and TEM images show CS hybrid are well wrapped with RGO layer, hindering polysulfide from dissolving in electrolyte, which explains the improvement of its electrochemical performance in lithium sulphur batteries.
Fig.2 SEM images of CS(a)and(b)RGO@CS.
XRD results further confirm the effective wrap-ping of RGO on CS surface.Sulphur contained in the RGO@CS and CS hybrid is in acrystalline state com-pared with the XRD pattern of crystal sulphur.Be-sides,the intensity of diffraction peaks of sulphur contained in RGO@CS gradually decreases and the peaks become less resolved and broadened compared with those of pure sulphur and CS,suggesting that the outside RGO layer may induce the scattering of the X-ray,in accordance with the TEM and SEM observa-tions.
The Raman spectra of the RGO@CS and CS are shown in Fig.5.Vibrational mode which can be as-signed to sulphur is observed in RGO@CS and CS. This is quite the same as pure sulphur,which has sev-eral vibration signals below500cm-1,indicating the sulphur is in the crystalline state.This result agrees well with the XRD results.Fig.5also shows the intensity ratio of D band and G band(I D/I G=1.76) of the RGO@CS is higher than those of RGO(I D/I G =1.52)and CS(I D/I G=1.42),owing to more de-fects appeared on the reduced graphene oxide layer as previously reported[30].
N2adsorption-desorption isotherms of the RGO@ CS show its specific surface area calculated by Brunauer-Emmett-Teller(BET)method is only about 3m2/g,which is slightly larger than CS hybrid (0.3m2/g)and much lower than the activated carbon (1789.3m2/g),indicating that the pores of activated carbon are filled with sulphur.Although RGO@CS shows a low specific surface area,the electrolyte can still fully access to the inner surface,which can be proved by the high capacity and power capability. The sulphur content in RGO@CS hybrid is43%,ac-cording to the TG analysis.The sulphur content de-creases with the increase of the amount of GO added,
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and the RGO@CS hybrid with sulphur fraction of 43%shows the best electrochemical performance, which is chosen for the following discussion.In order to eliminate the influences of sulphur fraction on the electrochemical performance,the CS hybrid with the same sulphur fraction was prepared for comparison.
Fig.3 TEM images of(a,b)RGO@CS and(c)corresponding elemental mapping of carbon(d)and sulphur.
Fig.4 XRD patterns of RGO@CS,CS,sulphur and dried GO. RGO@CS cathode demonstrates high capacities at high rates and relatively stable cyclic ability com-pared with the CS hybrid with the similar sulphur con-tent(42%),as shown in Fig.6and Fig.7.
Fig.5 Raman spectra of RGO@CS,CS,sulphur and RGO. The discharge capacity of RGO@CS electrode at the first cycle is about1578.3mAh/g,higher than 1050.8mAh/g of CS electrode.With an increase of current density(Fig.6),the discharge capacity of RGO@CS electrode is still much higher than that of
四213四新型炭材料第29卷
CS electrode at the same current desnity.A discharge capacity of598.2mAh/g can still be obtained even at 4.5A/g,which is much higher than that of CS elec-trode(94.5mAh/g).When the current density is switched back to0.15A/g,the capacity returns to 1100.6mAh/g,which is91.1%retention at a dis-charge rate of0.15A/g,indicative of the good cyclic stability of the RGO@CS cathode.Above results clearly show the introduction of graphene layer greatly improves the capacity and rate capability,indicating that the graphene layer acting as a barrier layer pre-vents the diffusion of polysulfide into bulk electrolyte and improves the utilization of the sulphur in the cath-ode system,which can also be proved by the greatly improved cyclic performance.
Fig.6 Rate performance of the RGO@CS and CS electrode under different current densities(0.15-4.5A/g).
Fig.7 Cyclic performances of the RGO@CS and CS
electrode under a current density of0.15A/g. The capacity of CS decreased dramatically and only187.2mAh/g was retained after160cycles, while the capacity of RGO@CS hybrid can still reach about450mAh/g(Fig.7).The capacity retention of RGO@CS electrode is11%higher than that of CS electrode,suggesting the sulphur utilization and the cyclic stability of RGO@CS are significantly improved by the addition of the graphene layer to form a core-shell structure.
The galvanostatic charge/discharge profiles of RGO@CS with different current densities(ranging from0.15to4.5A/g)within the potential range of 1.5-3.0V are shown in Fig.8.The voltage plateau with a low current density is consistent with the CV curve in Fig.9.With a current density of0.15A/g (Fig.8),RGO@CS displays a dischargecapacity of 1332.9mAh/g at the second cycle(based on the weight of sulphur).
Fig.8 Galvanostatic charge/discharge profiles of the RGO@CS
electrode with different current densities(0.15-4.5A/g).
Fig.9 CV curves of the RGO@CS electrode with a scan rate of 0.1mV/s within a potential range of1.5-3.0V(vs.Li+/Li). As shown in the CV curves(Fig.9),the reduc-tion peaks located at2.3V and2.1V are two typical reduction potentials of sulphur to a soluble polysulfide and further to the insoluble low-order S2-,respective-ly.An anodic peak can be observed at2.4V and is assigned to the oxidation of lithium sulfide to polysul-fide and further to element sulphur[6].The CV curve in the1st cycle exhibits broad peaks,which is likely to be related to the activation of the cell and the grad-ual enhancement of the sulphur utilization.And the peaks of2nd-4th curves have a relative high degree of overlap,suggesting highly reversible redox reactions in the cathode system.
4 Conclusions
We used the reduced graphene oxide layer as a barrier film to improve the cyclic stability of the acti-
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vated carbon/sulphur hybrid cathode material by forming a RGO@CS core-shell structure.The im-proved electrochemical properties of this hybrid mate-rial are attributed to the dual functions of the carbon components,which effectively restrain the sulphur and polysulfide inside the carbon pores and reduced graphene oxide in lithium sulphurre chargeable battery.This structure suppresses the shuttle effect of the sulphur cathode during charge-discharge process efficiently,demonstrated by a largely-im-proved capacity and a long term cyclic stability com-pared with the CS without RGO layer.We also pro-posed a simple approach to construct a graphene barri-er film on carbon surface by the changes of the hydro-philicity of graphene oxide during reduction process, which is versatile for any conditions to fabricate such kind of core-shell structure.This work provides a simple and promising strategy to improve the electro-chemical performance of the carbon/sulphur hybrid cathode,showing great potential in practical applica-tions.
References
[1] Bruce P G,Freunberger S A,Hardwick L J,et al.Li-O2and
Li-S batteries with high energy storage[J].Nature materials, 2011,11(1):19-29.
[2] Ji X,Nazar L F.Advances in Li-S batteries[J].Journal of Ma-
terials Chemistry,2010,20(44):9821-9826.
[3] Dominko R,Demir-Cakan R,Morcrette M,et al.Analytical de-
tection of soluble polysulphides in a modified Swagelok cell[J].
Electrochemistry Communications,2011,13(2):117-120. [4] Ji X,Lee K T,Nazar L F.A highly ordered nanostructured car-
bon-sulphur cathode for lithium-sulphur batteries[J].Nature ma-terials,2009,8(6):500-506.
[5]Yamin H,Peled E.Electrochemistry of a nonaqueous lithium/
sulphur cell[J].Journal of Power Sources,1983,9(3):281-287.
[6] Rauh R D,Shuker F S,Marston J M,et al.Formation of lithi-
um polysulfide in aprotic media[J].Journal of Inorganic and Nuclear Chemistry,1977,39(10):1761-1766.
[7] Ryu H S,Guo Z,Ahn H J,et al.Investigation of discharge re-
action mechanism of lithium|liquid electrolyte|sulphur battery [J].Journal of Power Sources,2009,189(2):1179-1183.
[8] Mikhaylik Y V,Akridge J R.Polysulfide shuttle study in the Li/
S battery system[J].Journal of the Electrochemical Society, 2004,151(11):A1969-A1976.
[9] Yang Y,Zheng G,Cui Y.Nanostructured sulphur cathodes[J].
Chemical Society Reviews,2013,42(7):3018-3032. [10] Wang J,Yang J,Xie J,et al.A novel conductive polymer-sul-
phur composite cathode material for rechargeable lithium batter-
ies[J].Advanced Materials,2002,14(13-14):963-965. [11] Seh Z W,Li W,Cha J J,et al.Sulphur-TiO2yolk-shell nano-
architecture with internal void space for long-cycle lithium-sul-
phur batteries[J].Nature communications,2013,4:1331.
[12] Wu F,Chen J,Chen R,et al.Sulphur/polythiophene with a
core/shell structure:Synthesis and electrochemical properties of
the cathode for rechargeable lithium batteries[J].The Journal
of Physical Chemistry C,2011,115(13):6057-6063. [13] Zheng G,Yang Y,Cha J J,et al.Hollow carbon nanofiber-en-
capsulated sulphur cathodes for high specific capacity recharge-
able lithium batteries[J].Nano letters,2011,11(10):4462-
4467.
[14] Liang C,Dudney N J,Howe J Y.Hierarchically structured sul-
phur/carbon nanocomposite material for high-energy lithium
battery[J].Chemistry of Materials,2009,21(19):4724-
4730.
[15] He G,Ji X,Nazar L.High C rate Li-S cathodes:sulphur
imbibed bimodal porous carbons[J].Energy&Environmental
Science,2011,4(8):2878-2883.
[16] Chen S R,Zhai Y P,Xu G L,et al.Ordered mesoporous car-
bon/sulphur nanocomposite of high performances as cathode for
lithium-sulphur battery[J].Electrochimica Acta,2011,56
(26):9549-9555.
[17] Demir-Cakan R,Morcrette M,Nouar F,et al.Cathode com-
posites for Li-S batteries via the use of oxygenated porous archi-
tectures[J].Journal of the American Chemical Society,2011,
133(40):16154-16160.
[18] Li X,Cao Y,Qi W,et al.Optimization of mesoporous carbon
structures for lithium-sulphur battery applications[J].Journal of
Materials Chemistry,2011,21(41):16603-16610. [19] Yuan L,Yuan H,Qiu X,et al.Improvement of cycle property
of sulphur-coated multi-walled carbon nanotubes composite
cathode for lithium/sulphur batteries[J].Journal of Power
Sources,2009,189(2):1141-1146.
[20] Evers S,Nazar L F.Graphene-enveloped sulphur in a one pot
reaction:a cathode with good coulombic efficiency and high
practical sulphur content[J].Chemical Communications,
2012,48(9):1233-1235.
[21] Wang J Z,Lu L,Choucair M,et al.Sulphur-graphene com-
posite for rechargeable lithium batteries[J].Journal of Power
Sources,2011,196(16):7030-7034.
[22] Cao Y,Li X,Aksay I A,et al.Sandwich-type functionalized
graphene sheet-sulphur nanocomposite for rechargeable lithium
batteries[J].Physical chemistry chemical physics,2011,13
(17):7660-7665.
[23] Wang H,Yang Y,Liang Y,et al.Graphene-wrapped sulphur
particles as a rechargeable lithium-sulphur battery cathode mate-
rial with high capacity and cycling stability[J].Nano letters,
2011,11(7):2644-2647.
[24]Jayaprakash N,Shen J,Moganty S S,et al.Porous hollow
carbon@sulphur composites for high-power lithium-sulphur
batteries[J].Angewandte Chemie,2011,50(26):5904-
5908.
[25] Zheng G,Yang Y,Cha J J,et al.Hollow carbon nanofiber-en-
capsulated sulphur cathodes for high specific capacity recharge-
able lithium batteries[J].Nano letters,2011,11(10):4462-
4467.
[26] Guo J,Xu Y,Wang C.Sulphur-impregnated disordered carbon
nanotubes cathode for lithium-sulphur batteries[J].Nano let-
ters,2011,11(10):4288-4294.
[27] Ji L,Rao M,Aloni S,et al.Porous carbon nanofiber-sulphur
composite electrodes for lithium/sulphur cells[J].Energy&
Environmental Science,2011,4(12):5053-5059.
四413四新型炭材料第29卷
[28] Elazari R ,Salitra G ,Garsuch A ,et al.Sulphur-impregnated
activated carbon fiber cloth as a binder-free cathode for re-chargeable Li-S batteries [J ].Advanced Materials ,2011,23
(47):5641-5644.
[29] Zhou G ,Yin L C ,Wang D W ,et al.Fibrous hybrid of gra-
phene and sulfur nanocrystals for high-performance lithium-sul-fur batteries [J ].ACS nano ,2013,7(6):5367-5375.
[30] Stankovich S ,Dikin D A ,Piner R D ,et al.Synthesis of gra-phene-based nanosheets via chemical reduction of exfoliated
graphite oxide [J ].Carbon ,2007,45(7):1558-1565
.‘新型炭材料“再创佳绩
2013年,‘新型炭材料“荣获中国出版政府奖期刊提名奖和全国 百强科技期刊 三中国出版政府奖是我国新闻出版领域的最高奖,旨在表彰和奖励国内新闻出版业优秀出版物二出版单位
和个人三本届评奖在全国一万多种期刊中共评选出期刊奖20种,期刊提名奖40种三
百强科技期刊 是为建立完善文化产品评价体系和激励机制,以报刊出版质量综合评估为抓手,实施
精品报刊建设工程三在全国范围内重点培育和推出的能建设社会主义核心价值观,建设学术理论创新体系,具有重要思想价值二科学价值或文化二艺术和学术价值的100家期刊三‘新型炭材料“近年来紧跟炭材料学科前沿,放眼国际研究领域,追踪热点二亮点,着力打造精品学术期
刊,学科内地位显著提升,国际影响力逐年增大
三
四5
13四第4期LI Fang-fei et al :Preparation and electrochemical performance of a graphene-wrapped
石墨烯包覆炭硫复合物正极材料的制备及其电化学性能
作者：李芳菲， 吕伟， 牛树章， 李宝华， LI Fang-fei， LU Wei， NIU Shu-zhang， LI Bao-hua
作者单位：李芳菲,牛树章,LI Fang-fei,NIU Shu-zhang(清华大学深圳研究生院 下一代动力与储能电池和炭功能材料工程实验室，广东 深圳 518055; 清华大学 材料学院先进材料教育部重点
实验室，北京 100084)， 吕伟,李宝华,LU Wei,LI Bao-hua(清华大学深圳研究生院 下一代
动力与储能电池和炭功能材料工程实验室,广东 深圳,518055)
刊名：
新型炭材料
英文刊名：New Carbon Materials
年，卷(期)：2014(4)
参考文献(30条)
1.Bruce P G;Freunberger S A;Hardwick L J Li-O2 and Li-S batteries with high energy storage 2011(01)
2.Ji X;Nazar L F Advances in Li-S batteries 2010(44)
3.Dominko R;Demir-Cakan R;Morcrette M Analytical de-tection of soluble polysulphides in a modified Swagelok cell 2011(02)
4.Ji X;Lee K T;Nazar L F A highly ordered nanostructured car-bon-sulphur cathode for lithium-sulphur batteries 2009(06)
5.Yamin H;Peled E Electrochemistry of a nonaqueous lithium/sulphur cell 1983(03)
6.Rauh R D;Shuker F S;Marston J M Formation of lithi-um polysulfide in aprotic media 1977(10)
7.Ryu H S;Guo Z;Ahn H J Investigation of discharge re-action mechanism of lithium | liquid electrolyte | sulphur battery 2009(02)
8.Mikhaylik Y V;Akridge J R Polysulfide shuttle study in the Li/S battery system 2004(11)
9.Yang Y;Zheng G;Cui Y Nanostructured sulphur cathodes 2013(07)
10.Wang J;Yang J;Xie J A novel conductive polymer-sul-phur composite cathode material for rechargeable lithium batter-ies 2002(13-14)
11.Seh Z W;Li W;Cha J J Sulphur-TiO2 yolk-shell nano-architecture with internal void space for long-cycle lithium-sul-phur batteries 2013
12.Wu F;Chen J;Chen R Sulphur/polythiophene with a core/shell structure:Synthesis and electrochemical properties of the cathode for rechargeable lithium batteries 2011(13)
13.Zheng G;Yang Y;Cha J J Hollow carbon nanofiber-en-capsulated sulphur cathodes for high specific capacity recharge-able lithium batteries 2011(10)
14.Liang C;Dudney N J;Howe J Y Hierarchically structured sul-phur/carbon nanocomposite material for high-energy lithium battery 2009(19)
15.He G;Ji X;Nazar L High " C” rate Li-S cathodes:sulphur imbibed bimodal porous carbons 2011(08)
16.Chen S R;Zhai Y P;Xu G L Ordered mesoporous car-bon/sulphur nanocomposite of high performances as cathode for lithium-sulphur battery 2011(26)
17.Demir-Cakan R;Morcrette M;Nouar F Cathode com-posites for Li-S batteries via the use of oxygenated porous archi-tectures 2011(40)
18.Li X;Cao Y;Qi W Optimization of mesoporous carbon structures for lithium-sulphur battery applications 2011(41)
19.Yuan L;Yuan H;Qiu X Improvement of cycle property of sulphur-coated multi-walled carbon nanotubes
composite cathode for lithium/sulphur batteries 2009(02)
20.Evers S;Nazar L F Graphene-enveloped sulphur in a one pot reaction:a cathode with good coulombic efficiency and high practical sulphur content 2012(09)
21.Wang J Z;Lu L;Choucair M Sulphur-graphene com-posite for rechargeable lithium batteries 2011(16)
22.Cao Y;Li X;Aksay I A Sandwich-type functionalized graphene sheet-sulphur nanocomposite for rechargeable lithium batteries 2011(17)
23.Wang H;Yang Y;Liang Y Graphene-wrapped sulphur particles as a rechargeable lithium-sulphur
battery cathode mate-rial with high capacity and cycling stability 2011(07)
24.Jayaprakash N;Shen J;Moganty S S Porous hollow carbon @ sulphur composites for high-power
lithium-sulphur batteries 2011(26)
25.Zheng G;Yang Y;Cha J J Hollow carbon nanofiber-en-capsulated sulphur cathodes for high specific capacity recharge-able lithium batteries 2011(10)
26.Guo J;Xu Y;Wang C Sulphur-impregnated disordered carbon nanotubes cathode for lithium-sulphur batteries 2011(10)
27.Ji L;Rao M;Aloni S Porous carbon nanofiber-sulphur composite electrodes for lithium/sulphur cells 2011(12)
28.Elazari R;Salitra G;Garsuch A Sulphur-impregnated activated carbon fiber cloth as a binder-free cathode for re-chargeable Li-S batteries 2011(47)
29.Zhou G;Yin L C;Wang D W Fibrous hybrid of gra-phene and sulfur nanocrystals for high-performance lithium-sul-fur batteries 2013(06)
30.Stankovich S;Dikin D A;Piner R D Synthesis of gra-phene-based nanosheets via chemical reduction of exfoliated graphite oxide 2007(07)
引用本文格式：李芳菲.吕伟.牛树章.李宝华.LI Fang-fei.LU Wei.NIU Shu-zhang.LI Bao-hua石墨烯包覆炭硫复合物正极材料的制备及其电化学性能[期刊论文]-新型炭材料 2014(4)