research article in situ carbon coated lini mn o cathode...

Research ArticleIn Situ Carbon Coated LiNi05Mn15O4 CathodeMaterial Prepared by Prepolymer of Melamine FormaldehydeResin Assisted Method

Wei Yang1 Haifeng Dang2 Shengzhou Chen1 Hanbo Zou1 Zili Liu1

Jing Lin1 and Weiming Lin13

1School of Chemistry and Chemical Engineering Guangzhou University 230 Waihuanxi Road Panyu DistrictGuangzhou 510006 China2School of Chemistry and Environmental Engineering Dongguan University of Technology Dongguan 523808 China3School of Chemistry and Chemical Engineering South China University of Technology 381Wushan Road Guangzhou 510640 China

Correspondence should be addressed to Shengzhou Chen szchengzhueducn

Received 31 August 2016 Accepted 7 November 2016

Academic Editor Subramaniam Ramesh

Copyright copy 2016 Wei Yang et alThis is an open access article distributed under the Creative CommonsAttribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Carbon coated spinel LiNi05Mn15O4were prepared by spray-drying using prepolymer of melamine formaldehyde resin (PMF)

as carbon source of carbon coating layer The PMF carbon coated LiNi05Mn15O4 was characterized by XRD SEM and otherelectrochemical measurements The as-prepared lithium nickel manganese oxide has the cubic face-centered spinel structure witha space group of Fd3m It showed good electrochemical performance as a cathode material for lithium ion battery After 100discharge and charge cycles at 05 C rate the specific discharge capacity of carbon coated LiNi05Mn15O4 was 130mAhsdotgminus1 and thecorresponding capacity retentionwas 988The 100th cycle specific discharge capacity at 10 C rate of carbon coated LiNi05Mn15O4was 1054mAhsdotgminus1 and even the corresponding capacity retention was 952

1 Introduction

Spinel LiNi05Mn15O4 is a promising and attractive cathodematerial because of its good electrochemical properties andhigh working potential (sim50V) [1ndash3] But the high ratedischarge capacity is far less than the theoretical capacitydue to low electronic conductivity and Li+ ion diffusioncoefficient of LiNi05Mn15O4 [4] Therefore many effortshave been devoted to enhance the electronic conductivity andLi+ ion diffusion coefficient by different synthesis routes [5ndash7] doping [8ndash12] and coating [13ndash16]

Carbon coating is easy and popular method at present[17] In our prophase research we found that the prepolymerof melamine formaldehyde resin would evenly coat on thesurface of metal oxide and obtained the carbon coatedmetal catalysts with abundant pore structure after hightemperature sintering [18] In this study in order to preparethe LiNi05Mn15O4 as well as to improve the high ratedischarge performance polymer-complex-assisted method

was applied Prepolymer of melamine formaldehyde resin(PMF) is used as carbon source to accomplish the carboncoated LiNi05Mn15O4

2 Experimental Sections

21 Material Synthesis The synthesis route was as followsLiOH Ni(NO3)2sdot6H2O and MnSO4sdotH2O were used as start-ing precursors with molar ratio of Li Ni Mn = 10 05 15Ni(NO3)2sdot6H2O and MnSO4sdotH2O were dispersed in deion-ized water under continuous stirring and then slowlydripped the (NH4)2C2O4 aqueous solution After reactionat 50∘C for 12 h then centrifugal washing to obtain theNi05Mn15(C2O4)2 precipitates Ni05Mn15(C2O4)2 LiOHand PMF (10wt) were dispersed in deionized water byultrasonic dispersion 30min into suspensionThe suspensionwas dried by spray-drying method (inlet temperature 220∘Cand feed rate 6mLsdotmin)The dried products were presintered

Hindawi Publishing CorporationInternational Journal of Polymer ScienceVolume 2016 Article ID 4279457 5 pageshttpdxdoiorg10115520164279457

2 International Journal of Polymer Science

at 500∘C in N2 atmosphere for 5 h and then sintered at800∘C in N2 atmosphere for 20 h to obtain the carbon coatedLiNi05Mn15O4 For comparison LiNi05Mn15O4 was alsosynthesized without PMF

22 Characterization The structure of the LiNi05Mn15O4materials was characterized using powder X-ray diffraction(XRD XD-3 Beijing Purkinje General China) with CuK120572 radiation at 36 kV and 20mA The morphology ofLiNi05Mn15O4 was identified by field emission scanningelectron microscopy (FE-SEM JSM-5600 JEOL Japan)

For electrochemical characterizations 2032 type coincells were used The coin-type cells (2032) were assembledwith Li plate as anode and LiNi05Mn15O4 electrode ascathode The LiNi05Mn15O4 electrodes were prepared bycoating the slurry of a mixture composed of LiNi05Mn15O4(80wt) conducting agent (Super-p 10 wt) and binder(polyvinylidene difluoride 10 wt) onto an aluminum foiland then dried at 120∘C for 24 h in a vacuum drier Theweight of active material in the LiNi05Mn15O4 electrodewas 30mgsdotcmminus2 The electrolyte was 1molsdotLminus1 LiPF6 in themixture of ethylene carbonate (EC) and dimethyl carbon-ate (DMC) with a volume ratio of 1 1 A polypropylene(PP) film (Celgard 2300) was used as the separator After-wards the coin-type cells were assembled in argon-filledglove box NEWARE multichannel battery-testing unit (CT-3008W China) was employed to test the cycling and rateperformances of LiNi05Mn15O4 over a voltage range between35 and 50V versus LiLi+ electrode at room temperatureFirstly the cell should discharge and charge two cycles at05 C and then discharge and charge 100 cycles at differentrates The cyclic voltammetric (CV) tests were carried outon an electrochemical workstation (CHI660A) at a scanrate of 01mVsdotsminus1 in the range of 35ndash50V versus LiLi+The electrochemical impedance spectroscopy (EIS) data ofthe electrodes were acquired at room temperature by aelectrochemical workstation (CHI660A) before cycling in thefrequency range 10mHzndash100 kHz by imposing an alternatecurrent with an amplitude of 10mV on the electrode

3 Results and Discussion

Figure 1 shows the XRD pattern of the as-preparedLiNi05Mn15O4 Compared with the PDF powder diffractiondata file (JCPDS Card No 80-2162) the diffraction peaksof as-prepared LiNi05Mn15O4 are in agreement with thestandard diffraction peaks This illustrates that the as-prepared LiNi05Mn15O4 has the cubic face-centered spinelstructure with a space group of Fd3m [19]There is no changeof the station of diffraction peak after carbon coating and nocoating The diffraction peak intensity would be enhancedafter PMF carbon coating The carbon coating would behelpful to improve LiNi05Mn15O4 crystallinity Figure 2shows FE-SEM images of LiNi05Mn15O4 with no coatingand after 10wt PMF carbon coating The LiNi05Mn15O4maintains the micronanostructure after carbon coating butthe surface of samples becomes roughed and the roughness

(622

)(5

33)

(531

)(440

)

(511

)

(331

)

(400

)

(222

)(3

11)

(111

)

PMF-10

No-PMF

Inte

nsity

(au

)

PDF80-2162

20 30 40 50 60 70 80102120579 (∘)

Figure 1 XRD patterns of prepared LiNi05Mn15O4

of samples increases after the PMF carbon coating Thedegree of sphericity drops gradually

Figure 3 shows the 2nd 50th and 100th charge anddischarge curves of carbon coated LiNi05Mn15O4 at the rateof 05 C The specific discharge capacity of LiNi05Mn15O4increased after PMF carbon coating at around 47V voltageplateauThe 2nd cycle specific discharge capacity raised from1251mAhsdotgminus1 (no coating) to 1317mAhsdotgminus1 (after coating)After 100 discharge and charge cycles the specific dischargecapacity of carbon coated LiNi05Mn15O4 was 130mAhsdotgminus1and even the corresponding capacity retention was 988And yet the specific discharge capacity of no coatedLiNi05Mn15O4 was 889mAhsdotgminus1 and the correspondingcapacity retentionwas 711Thedischarge and charge curvesindicate that the PMF carbon coating reduces the electrodepolarization after repeatedly charging and discharging cyclewhich suggests that PMF coating was in favour of improvingthe discharge and charge performance of lithium nickelmanganese oxide materials Another reason might be thatthe PMF carbon coating prevents the Mn3+ dissolving in theprocess of charging and discharging thereby reducing thefading rate of discharge capacity [20 21]

Figure 4 shows the 2nd 50th and 100th charge anddischarge curves of carbon coated LiNi05Mn15O4 at the rateof 10 C The specific discharge capacity of LiNi05Mn15O4declines sharply after PMF carbon coating at high ratedischargeThe 2nd cycle specific discharge capacity decreasedfrom 1179mAhsdotgminus1 (before coating) to 1106mAhsdotgminus1 (aftercoating) The PMF carbon coating hinders the Li+ ionicconduction at high rate discharge and charge But the corre-sponding capacity retention was greatly improved after PMFcarbon coatingThe 100th cycle specific discharge capacity ofcarbon coated LiNi05Mn15O4 was 1054mAhsdotgminus1 and eventhe corresponding capacity retention was 952 And yet thespecific discharge capacity of no coated LiNi05Mn15O4 was854mAhsdotgminus1 the corresponding capacity retention was691

Figure 5 shows the CV curves of the PMF carbon coatedLiNi05Mn15O4 electrode In the full range view of CV curves

International Journal of Polymer Science 3

Figure 2 FE-SEM images of prepared LiNi05Mn15O4

2nd50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)

20 40 60 80 100 120 1400Capacity (mAhmiddotgminus1)

(a) No-PMF

2nd 50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(b) PMF-10

Figure 3 The charge and discharge curves of prepared LiNi05Mn15O4 at 05 C

one pair of redox peaks around 4V (Mn3+Mn4+) and twopairs of well separated strong redox peaks at 46ndash48V can beobserved in CV curve of no carbon coated LiNi05Mn15O4electrode The two strong redox peaks indicate a two-stage(Ni2+Ni3+ and Ni3+Ni4+) Li+ extraction from or insertioninto the spinel framework [22] For PMF carbon coatedLiNi05Mn15O4 electrode the peaks around 4V shouldweaken obviously This indicates that the Mn3+ ions disso-lution amount of the PMF carbon coated LiNi05Mn15O4 issmaller than no carbon coating [23]The presence ofMn3+ inthe LMNO material plays an important role in the capacityretention [9] And the two redox peaks of LiNi05Mn15O4with 10wt PMF carbon coating are overlapped to a broadpeak The cyclic voltammetry curves of the PMF carboncoated LiNi05Mn15O4 material exhibit smaller potentialintervals that indicated higher electrode reaction reversibilityand lower polarization The PMF carbon coating would

effectively restrain the Mn3+ stripping and the side reactionbetween positive electrode active material and electrolyte athigh voltage

Figure 6 depicts the electrochemical impedance spec-troscopy of the electrode obtained after the first cycleof charge The semicircle at high frequency (gt100Hz) inEIS spectra reflects the contact resistances between theactive materials and electrolyte or current collector [24]The significant improvements in electric conductivity forLiNi05Mn15O4 electrode could therefore be attributed to thePMF carbon coating [25]

4 Conclusions

PMF carbon coated LiNi05Mn15O4 was prepared as the5V cathode materials of lithium ion batteries for the firsttime PMF carbon coating increases the crystallinity of


2nd50th100th

33

36

39

42

45

48

51Vo

ltage

(V)

20 40 60 80 100 1200Capacity (mAhmiddotgminus1)

(a) No-PMF

2nd 50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(b) PMF-10


No-PMF PMF-10

minus06

minus03

00

03

06

09

I(m

Amiddotg

minus1)

35 40 45 5030E (V versus Li+Li)

Figure 5 Cyclic voltammogram curves of prepared LiNi05Mn15O4

LiNi05Mn15O4 The as-prepared LiNi05Mn15O4 has thecubic face-centered spinel structure with a space group ofFd3m The PMF carbon coating greatly promotes electro-chemical performance and reduces the LiNi05Mn15O4 elec-trode polarization in the process of charging and dischargingThe cycle life of LiNi05Mn15O4 was significantly improved byPMF carbon coating especially at high rate discharging andcharging

Competing Interests

The authors declare that they have no competing interests

No-PMF PMF-10

0

100

200

300

400

500

minusZ

998400998400(Ω

)

100 200 300 400 5000Z998400 (Ω)

Q Q

Figure 6 EIS spectra of prepared LiNi05Mn15O4

Acknowledgments

This work was supported by the National Natural ScienceFoundation of China (no 21376056 and no 21463030)China Postdoctoral Science Foundation (2016M590781)and Science and Technology Project of Guangzhou (no201509030005 and no 201510010131)

References

[1] R SanthanamandB Rambabu ldquoResearch progress in high volt-age spinel LiNi05Mn15O4 materialrdquo Journal of Power Sourcesvol 195 no 17 pp 5442ndash5451 2010


[2] H-S Fang Z-X Wang X-H Li H-J Guo and W-J PengldquoExploration of high capacity LiNi05Mn15O4 synthesized bysolid-state reactionrdquo Journal of Power Sources vol 153 no 1 pp174ndash176 2006

[3] YQian YDeng Z Shi Y ZhouQ Zhuang andGChen ldquoSub-micrometer-sized LiMn

15Ni05O4spheres as high rate cathode

materials for long-life lithium ion batteriesrdquo ElectrochemistryCommunications vol 27 pp 92ndash95 2013

[4] J-H Kim N P W Pieczonka Z Li Y Wu S Harris and BR Powell ldquoUnderstanding the capacity fading mechanism inLiNi05Mn15O4graphite Li-ion batteriesrdquo Electrochimica Actavol 90 pp 556ndash562 2013

[5] D Liu J Han and J B Goodenough ldquoStructure morphologyand cathode performance of Li1-x[Ni05Mn15]O4 prepared bycoprecipitation with oxalic acidrdquo Journal of Power Sources vol195 no 9 pp 2918ndash2923 2010

[6] Y-C Jin and J-G Duh ldquoNanostructured LiNi05Mn15O4 cath-ode material synthesized by polymer-assisted co-precipitationmethodwith improved rate capabilityrdquoMaterials Letters vol 93no 2 pp 77ndash80 2013

[7] L Wang D Chen J Wang G Liu W Wu and G LiangldquoSynthesis of LiNi05Mn15O4 cathode material with improvedelectrochemical performances through a modified solid-statemethodrdquo Powder Technology vol 292 pp 203ndash209 2016

[8] J Hassoun K-S Lee Y-K Sun and B Scrosati ldquoAn advancedlithium ion battery based on high performance electrodematerialsrdquo Journal of the American Chemical Society vol 133no 9 pp 3139ndash3143 2011

[9] J Xiao X Chen P V Sushko et al ldquoHigh-performanceLiNi05Mn15O4 Spinel controlled by Mn3+ concentration andsite disorderrdquoAdvancedMaterials vol 24 no 16 pp 2109ndash21162012

[10] J Deng Y Xu L Xiong L Li X Sun and Y Zhang ldquoImprovingthe fast discharge performance of high-voltage LiNi05Mn15O4spinel by Cu2+ Al3+ Ti4+ tri-dopingrdquo Journal of Alloys andCompounds vol 677 no 8 pp 18ndash26 2016

[11] G Liu Y Du W Liu and L Wen ldquoStudy on the action mecha-nism of doping transitional elements in spinel LiNi05Mn15O4rdquoElectrochimica Acta vol 209 pp 308ndash314 2016

[12] S Wang P Li L Shao et al ldquoPreparation of spinelLiNi05Mn15O4 and Cr-doped LiNi05Mn15O4 cathodematerials by tartaric acid assisted sol-gel methodrdquo CeramicsInternational vol 41 no 1 pp 1347ndash1353 2015

[13] Y S Lee Y K Sun S Ota T Miyashita andM Yoshio ldquoPrepa-ration and characterization of nano-crystalline LiNi05Mn15O4for 5V cathode material by composite carbonate processrdquoElectrochemistry Communications vol 4 no 12 pp 989ndash9942002

[14] H B Yao Y Xie G J Han and D M Jia ldquoEnhanced electro-chemical performance of the cathode material LiNi05Mn15O4embedded by CNTsrdquo Journal of Materials Science Materials inElectronics vol 26 no 3 pp 1780ndash1783 2015

[15] X LiWGuo Y LiuWHe and Z Xiao ldquoSpinel LiNi05Mn15O4as superior electrode materials for lithium-ion batteries ionicliquid assisted synthesis and the effect of CuO coatingrdquo Elec-trochimica Acta vol 116 no 1 pp 278ndash283 2014

[16] THwang J K Lee JMun andWChoi ldquoSurface-modified car-bon nanotube coating on high-voltage LiNi05Mn15O4 cathodesfor lithium ion batteriesrdquo Journal of Power Sources vol 322 no8 pp 40ndash48 2016

[17] A Vijn F Hoffmann and M Froba ldquoThermal conversion toform LiNi05Mn15O4minus120575 Influence of precursors and supporting

carbon template materialsrdquo Thermochimica Acta vol 638 pp138ndash150 2016

[18] Y Wei C Shengzhou and L Weiming ldquoOxygen reduction onnon-noblemetal electrocatalysts supported onN-doped carbonaerogel compositesrdquo International Journal of Hydrogen Energyvol 37 no 1 pp 942ndash945 2012

[19] Y-J Gu Y Li Y-B Chen and H-Q Liu ldquoComparison ofLiNi antisite defects in Fd-3 m and P4332 nanostructuredLiNi05Mn15O4 electrode for Li-ion batteriesrdquo ElectrochimicaActa vol 213 no 9 pp 368ndash374 2016

[20] H Wang Z Shi J Li et al ldquoDirect carbon coating at hightemperature on LiNi05Mn15O4 cathode unexpected influenceon crystal structure and electrochemical performancesrdquo Journalof Power Sources vol 288 no 8 pp 206ndash213 2015

[21] G Jia C Jiao W Xue et al ldquoImprovement in electrochemicalperformance of calcined LiNi

05Mn15O4GOrdquo Solid State Ionics

vol 292 no 9 pp 15ndash21 2016[22] L Zhou D Y Zhao and X W Lou ldquoLiNi

05Mn15O4hollow

structures as high-performance cathodes for lithium-ion bat-teriesrdquoAngewandte Chemie International Edition vol 124 no 1pp 243ndash245 2012

[23] J Liu and A Manthiram ldquoUnderstanding the improved elec-trochemical performances of Fe-substituted 5 V spinel cathodeLiMn15Ni05O4rdquo Journal of Physical Chemistry C vol 113 no 33pp 15073ndash15079 2009

[24] Q-C Zhuang T Wei L-L Du Y-L Cui L Fang and S-GSun ldquoAn electrochemical impedance spectroscopic study of theelectronic and ionic transport properties of spinel LiMn2O4rdquoThe Journal of Physical Chemistry C vol 114 no 18 pp 8614ndash8621 2010

[25] T Yang N Zhang Y Lang and K Sun ldquoEnhanced rate perfor-mance of carbon-coated LiNi05Mn15O4 cathode material forlithium ion batteriesrdquo Electrochimica Acta vol 56 no 11 pp4058ndash4064 2011

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



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CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


at 500∘C in N2 atmosphere for 5 h and then sintered at800∘C in N2 atmosphere for 20 h to obtain the carbon coatedLiNi05Mn15O4 For comparison LiNi05Mn15O4 was alsosynthesized without PMF

22 Characterization The structure of the LiNi05Mn15O4materials was characterized using powder X-ray diffraction(XRD XD-3 Beijing Purkinje General China) with CuK120572 radiation at 36 kV and 20mA The morphology ofLiNi05Mn15O4 was identified by field emission scanningelectron microscopy (FE-SEM JSM-5600 JEOL Japan)

For electrochemical characterizations 2032 type coincells were used The coin-type cells (2032) were assembledwith Li plate as anode and LiNi05Mn15O4 electrode ascathode The LiNi05Mn15O4 electrodes were prepared bycoating the slurry of a mixture composed of LiNi05Mn15O4(80wt) conducting agent (Super-p 10 wt) and binder(polyvinylidene difluoride 10 wt) onto an aluminum foiland then dried at 120∘C for 24 h in a vacuum drier Theweight of active material in the LiNi05Mn15O4 electrodewas 30mgsdotcmminus2 The electrolyte was 1molsdotLminus1 LiPF6 in themixture of ethylene carbonate (EC) and dimethyl carbon-ate (DMC) with a volume ratio of 1 1 A polypropylene(PP) film (Celgard 2300) was used as the separator After-wards the coin-type cells were assembled in argon-filledglove box NEWARE multichannel battery-testing unit (CT-3008W China) was employed to test the cycling and rateperformances of LiNi05Mn15O4 over a voltage range between35 and 50V versus LiLi+ electrode at room temperatureFirstly the cell should discharge and charge two cycles at05 C and then discharge and charge 100 cycles at differentrates The cyclic voltammetric (CV) tests were carried outon an electrochemical workstation (CHI660A) at a scanrate of 01mVsdotsminus1 in the range of 35ndash50V versus LiLi+The electrochemical impedance spectroscopy (EIS) data ofthe electrodes were acquired at room temperature by aelectrochemical workstation (CHI660A) before cycling in thefrequency range 10mHzndash100 kHz by imposing an alternatecurrent with an amplitude of 10mV on the electrode

3 Results and Discussion

Figure 1 shows the XRD pattern of the as-preparedLiNi05Mn15O4 Compared with the PDF powder diffractiondata file (JCPDS Card No 80-2162) the diffraction peaksof as-prepared LiNi05Mn15O4 are in agreement with thestandard diffraction peaks This illustrates that the as-prepared LiNi05Mn15O4 has the cubic face-centered spinelstructure with a space group of Fd3m [19]There is no changeof the station of diffraction peak after carbon coating and nocoating The diffraction peak intensity would be enhancedafter PMF carbon coating The carbon coating would behelpful to improve LiNi05Mn15O4 crystallinity Figure 2shows FE-SEM images of LiNi05Mn15O4 with no coatingand after 10wt PMF carbon coating The LiNi05Mn15O4maintains the micronanostructure after carbon coating butthe surface of samples becomes roughed and the roughness

(622

)(5

33)

(531

)(440

)

(511

)

(331

)

(400

)

(222

)(3

11)

(111

)

PMF-10

No-PMF

Inte

nsity

(au

)

PDF80-2162

20 30 40 50 60 70 80102120579 (∘)

Figure 1 XRD patterns of prepared LiNi05Mn15O4

of samples increases after the PMF carbon coating Thedegree of sphericity drops gradually

Figure 3 shows the 2nd 50th and 100th charge anddischarge curves of carbon coated LiNi05Mn15O4 at the rateof 05 C The specific discharge capacity of LiNi05Mn15O4increased after PMF carbon coating at around 47V voltageplateauThe 2nd cycle specific discharge capacity raised from1251mAhsdotgminus1 (no coating) to 1317mAhsdotgminus1 (after coating)After 100 discharge and charge cycles the specific dischargecapacity of carbon coated LiNi05Mn15O4 was 130mAhsdotgminus1and even the corresponding capacity retention was 988And yet the specific discharge capacity of no coatedLiNi05Mn15O4 was 889mAhsdotgminus1 and the correspondingcapacity retentionwas 711Thedischarge and charge curvesindicate that the PMF carbon coating reduces the electrodepolarization after repeatedly charging and discharging cyclewhich suggests that PMF coating was in favour of improvingthe discharge and charge performance of lithium nickelmanganese oxide materials Another reason might be thatthe PMF carbon coating prevents the Mn3+ dissolving in theprocess of charging and discharging thereby reducing thefading rate of discharge capacity [20 21]

Figure 4 shows the 2nd 50th and 100th charge anddischarge curves of carbon coated LiNi05Mn15O4 at the rateof 10 C The specific discharge capacity of LiNi05Mn15O4declines sharply after PMF carbon coating at high ratedischargeThe 2nd cycle specific discharge capacity decreasedfrom 1179mAhsdotgminus1 (before coating) to 1106mAhsdotgminus1 (aftercoating) The PMF carbon coating hinders the Li+ ionicconduction at high rate discharge and charge But the corre-sponding capacity retention was greatly improved after PMFcarbon coatingThe 100th cycle specific discharge capacity ofcarbon coated LiNi05Mn15O4 was 1054mAhsdotgminus1 and eventhe corresponding capacity retention was 952 And yet thespecific discharge capacity of no coated LiNi05Mn15O4 was854mAhsdotgminus1 the corresponding capacity retention was691

Figure 5 shows the CV curves of the PMF carbon coatedLiNi05Mn15O4 electrode In the full range view of CV curves



2nd50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(a) No-PMF

2nd 50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(b) PMF-10





4 Conclusions



2nd50th100th

33

36

39

42

45

48

51Vo

ltage

(V)


(a) No-PMF

2nd 50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(b) PMF-10


No-PMF PMF-10

minus06

minus03

00

03

06

09

I(m

Amiddotg

minus1)

35 40 45 5030E (V versus Li+Li)



Competing Interests


No-PMF PMF-10

0

100

200

300

400

500

minusZ

998400998400(Ω

)

100 200 300 400 5000Z998400 (Ω)

Q Q


Acknowledgments


References




























05Mn15O4hollow












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





2nd50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(a) No-PMF

2nd 50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(b) PMF-10





4 Conclusions



2nd50th100th

33

36

39

42

45

48

51Vo

ltage

(V)


(a) No-PMF

2nd 50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(b) PMF-10


No-PMF PMF-10

minus06

minus03

00

03

06

09

I(m

Amiddotg

minus1)

35 40 45 5030E (V versus Li+Li)



Competing Interests


No-PMF PMF-10

0

100

200

300

400

500

minusZ

998400998400(Ω

)

100 200 300 400 5000Z998400 (Ω)

Q Q


Acknowledgments


References




























05Mn15O4hollow












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




2nd50th100th

33

36

39

42

45

48

51Vo

ltage

(V)


(a) No-PMF

2nd 50th 100th

33

36

39

42

45

48

51

Volta

ge (V

)


(b) PMF-10


No-PMF PMF-10

minus06

minus03

00

03

06

09

I(m

Amiddotg

minus1)

35 40 45 5030E (V versus Li+Li)



Competing Interests


No-PMF PMF-10

0

100

200

300

400

500

minusZ

998400998400(Ω

)

100 200 300 400 5000Z998400 (Ω)

Q Q


Acknowledgments


References




























05Mn15O4hollow












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





























05Mn15O4hollow












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



research article in situ carbon coated lini mn o cathode...

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