Nanocrystalline LiCrTiO4 as anode for asymmetric hybrid supercapacitor

3 of 43) 1402225 wileyonlinelibrary.comhost matrix is observed and this process is called "topotactic reaction", which is either chemically or thermally reversible; a perfect example is Li-intercalation into a graphite matrix. Such intercalation chemistry has been successfully used in Li-ion batteries for both anode and cathode materials and has also been commercialized (i.e., LiCoO 2 /Li x C 6 and LiFePO 4 /Li x C 6 ). [ 4,5 ] The insertion type materials, i.e., metal oxides have several advantages over graphitic anodes when used in practical cells; these include a negligible amount of ICL, no Li-platting issues, no solvent co-intercalation, no electrolyte decomposition, no SEI required for the safe operation of the cell, it is capable of delivering high power density, and has an easy synthesis protocol. On the other hand, less reversible capacity and higher intercalation potential are the notable setbacks compared to graphite. Although numerous Li-intercalating materials are proposed as possible anodes for LIB applications, few of them have only been tested or commercialized in the "rocking-chair" confi guration, for instance Li 4 Ti 5 O 5 anode. Apart from the mentioned anode, few other insertion type materials have been also evaluated in the rocking-chair confi guration for LIBs. Accordingly, the next section describes the structural and electrochemical performance of various intercalation anodes evaluated in the rocking-chair confi guration. TiO 2The existence of several polymorphs is reported for the case of TiO 2 , but anatase, rutile, brookite, and bronze phases have only been reported for Li-storage. [ 26 ] Reversible insertion of one mole of Li is theoretically possible, independent of the polymorph, with a capacity of ≈335 mAh g −1 . However, variation in the Liinsertion potential and reaction mechanism has been observed for such polymorphs. Easy synthesis protocols, scalability, inexpensiveness, ease of tailoring the desired morphology, and eco-friendliness are other key features for utilizing TiO 2 polymorphs for the construction of Li-ion power packs. [27][28][29] AnataseThe anatase phase is one of the widely investigated polymorphs of TiO 2 for Li-storage. [ 27 ] Theoretically, one mole of Li is possible, but practically only ≈0.5 mole Li is reversible upon cycling. Several research attempts have been carried out to improve the reversible capacity, including utilizing high energy (0 0 1) facets because of their dominant higher surface energy (0.90 J m −2 ) compared to (1 0 0) facets (0.44 J m −2 ) and using thermodynamically more stable (1 0 1) facets (0.53 J m −2 ). [ 30,31 ] Although high Li-reversibility could be achieved for such (0 0 1) facets, capacity fading remains an issue upon cycling. [ 32 ] Li-diffusion co-effi cient ( D Li ) values for anatase phase are in the range of 1 × 10 −17 to 4 × 10 −17 cm 2 s −1 for Li-insertion and extraction processes, respectively. [ 27 ] In the crystal chemistry of the anatase phase, TiO 6 octahedra sharetwo adjacent edges with two other octahedral so that...

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“…Li). [ 264,271 ] On the other hand, a Ti 4+/3+ redox couple could be used as a promising ≈1.5 V vs .…”

Section: Liti 2 Omentioning

confidence: 99%

Research Progress on Negative Electrodes for Practical Li‐Ion Batteries: Beyond Carbonaceous Anodes

Aravindan

Lee

Srinivasan

2015

Advanced Energy Materials

433

319

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“…The configuration delivers the practical energy density of ~ 12 Wh kg −1 with reasonable power density1. Since then, several Li-insertion type electrodes such as LiNi 0.5 Mn 1.5 O 4 910, LiMn 2 O 4 11, LiFePO 4 12, LiCoPO 4 13, Li 2 MnSiO 4 14, Li 2 FeSiO 4 15, MnO 2 16, V 2 O 5 17, β-FeOOH18, Li 4 Ti 5 O 12 12192021, TiO 2 -B2223, TiP 2 O 7 24, LiTi 2 (PO 4 ) 3 25, and LiCrTiO 4 2627 have been explored along with high surface area carbonaceous material as counter electrode. Among the insertion type electrodes proposed, spinel phase Li 4 Ti 5 O 12 is found noteworthy due to its salient features such as (i) very high columbic efficiency (>95% at high current rates) with practical capacity close to the theoretical capacity of 175 mAh g −1 for reversible insertion of three moles of Li, (ii) thermodynamically flat discharge profile at ~ 1.55 V vs. Li corresponding to the two-phase insertion/extraction mechanism, (iii) zero-strain insertion that provides no volume change during charge–discharge process, (iv) no solid electrolyte interface (SEI) formation, (v) inexpensive raw materials, (vi) ease of preparation and (vii) eco-friendliness42021.…”

mentioning

confidence: 99%

Activated carbons derived from coconut shells as high energy density cathode material for Li-ion capacitors

Jain

Aravindan

Jayaraman

et al. 2013

Sci Rep

230

149

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In this manuscript, a dramatic increase in the energy density of ~ 69 Wh kg−1 and an extraordinary cycleability ~ 2000 cycles of the Li-ion hybrid electrochemical capacitors (Li-HEC) is achieved by employing tailored activated carbon (AC) of ~ 60% mesoporosity derived from coconut shells (CS). The AC is obtained by both physical and chemical hydrothermal carbonization activation process, and compared to the commercial AC powders (CAC) in terms of the supercapacitance performance in single electrode configuration vs. Li. The Li-HEC is fabricated with commercially available Li4Ti5O12 anode and the coconut shell derived AC as cathode in non-aqueous medium. The present research provides a new routine for the development of high energy density Li-HEC that employs a mesoporous carbonaceous electrode derived from bio-mass precursors.

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“…This hybrid energy storage device is considered to be a promising power source for EVs. [3][4][5][6][7][8][9][10][11][12][13][14] AC/Li 4 Ti 5 O 12 hybrid supercapacitor exhibits high rate capability but low energy density. 5,[15][16][17][18][19] Its energy density can be improved via the addition of positive electrode materials of Li-ion batteries, e.g., LiCoO 2 , 20 LiMn 2 O 4 , 21,22 and LiFePO 4 23-25 to the AC electrode.…”

Section: Introductionmentioning

confidence: 99%

(LiFePO4-AC)/Li4Ti5O12 hybrid supercapacitor: The effect of LiFePO4 content on its performance

Chen

Wang

et al. 2012

Journal of Renewable and Sustainable Energy

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Eosin yellowish dye sensitized TiO2 solar cell with PEG/PEO/LiI/I2 as electrolyte AIP Conf.Composites of LiFePO 4 and activated carbon (LFP-AC) were prepared by a ball milling method. Their morphologies were investigated by scanning electronic microscopy and energy dispersive spectroscopy. Hybrid supercapacitors were assembled using the LFP-AC composites as the positive electrode and Li 4 Ti 5 O 12 as the negative electrode (LFP-AC/Li 4 Ti 5 O 12 ). Effects of the positive electrode composition (ratio of LiFePO 4 to AC) on the performance of LFP-AC/Li 4 Ti 5 O 12 were investigated via constant current charge-discharge tests. The results demonstrated that the specific capacity and the specific power of the LFP-AC/ Li 4 Ti 5 O 12 hybrid supercapacitor significantly depend upon the content of LiFePO 4 in the LFP-AC positive electrode. At 0.5 A g À1 charge-discharge current, the specific capacity of the LFP-AC/Li 4 Ti 5 O 12 with 30 wt. % LiFePO 4 and 70 wt. % AC in the positive electrode is 42% higher than that of AC/Li 4 Ti 5 O 12 , and the two supercapacitors have the same specific power. After 500 charge-discharge cycles at 1.0 A g À1 , the specific capacity of the LFP-AC/Li 4 Ti 5 O 12 with 80 wt. % LiFePO 4 and 20 wt. % AC in the positive electrode is 53% higher than that of AC/Li 4 Ti 5 O 12 . The hybrid device stores electric energy via both the double-layer electrostatic adsorption and the intercalation/deintercalation of lithium ions. V C 2012 American Institute of Physics. [http://dx.

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Nanocrystalline LiCrTiO4 as anode for asymmetric hybrid supercapacitor

Cited by 59 publications

References 26 publications

Research Progress on Negative Electrodes for Practical Li‐Ion Batteries: Beyond Carbonaceous Anodes

Research Progress on Negative Electrodes for Practical Li‐Ion Batteries: Beyond Carbonaceous Anodes

Activated carbons derived from coconut shells as high energy density cathode material for Li-ion capacitors

(LiFePO4-AC)/Li4Ti5O12 hybrid supercapacitor: The effect of LiFePO4 content on its performance

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