03039nas a2200205   4500008004100000022001300041245012800054210006900182300001600251490000600267520228200273100002302555700002302578700001802601700002702619700002302646700002002669700001802689856012602707       2018                        eng d  a2046206900aStructural elucidation of NASICON (Na3Al2P3O12) based glass electrolyte materials: effective influence of boron and gallium0 aStructural elucidation of NASICON Na3Al2P3O12 based glass electr  a14422-144330 v83 a<p>Understanding the conductivity variations induced by compositional changes in sodium super ionic conducting (NASICON) glass materials is highly relevant for applications such as solid electrolytes for sodium (Na) ion batteries. In the research reported in this paper, NASICON-based NCAP glass (Na2.8Ca0.1Al2P3O12) was selected as the parent glass. The present study demonstrates the changes in the Na+ ion conductivity of NCAP bulk glass with the substitution of boron (NCABP: Na2.8Ca0.1Al2B0.5P2.7O12) and gallium (NCAGP: Na2.8Ca0.1Al2Ga0.5P2.7O12) for phosphorus and the resulting structural variations found in the glass network. For a detailed structural analysis of NCAP, NCABP and NCAGP glasses, micro-Raman and magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopic techniques (for 31P, 27Al, 23Na, 11B and 71Ga nuclei) were used. The Raman spectrum revealed that the NCAP glass structure is more analogous to the AlPO4 mesoporous glass structure. The 31P MAS-NMR spectrum illustrated that the NCAP glass structure consists of a high concentration of Q0 (3Al) units, followed by Q0 (2Al) units. The 27Al MAS-NMR spectrum indicates that alumina exists at five different sites, which include AlO4 units surrounded by AlO6 units, Al(OP)4, Al(OP)5, Al(OAl)6 and Al(OP)6, in the NCAP glass structure. The 31P, 27Al and 11B MAS-NMR spectra of the NCABP glass revealed the absence of B–O–Al linkages and the presence of B3–O–B4–O–P4 linkages which further leads to the formation of borate and borophosphate domains. The 71Ga MAS-NMR spectrum suggests that gallium cations in the NCAGP glass compete with the alumina cations and occupy four (GaO4), five (GaO5) and six (GaO6) coordinated sites. The Raman spectrum of NCAGP glass indicates that sodium cations have also been substituted by gallium cations in the NCAP glass structure. From impedance analysis, the dc conductivity of the NCAP glass (∼3.13 × 10−8 S cm−1) is slightly decreased with the substitution of gallium (∼2.27 × 10−8 S cm−1) but considerably decreased with the substitution of boron (∼1.46 × 10−8 S cm−1). The variation in the conductivity values are described based on the structural changes of NCAP glass with the substitution of gallium and boron.</p>1 aAllu, Amarnath, R.1 aBalaji, Sathravada1 aIllath, Kavya1 aHareendran, Chaithanya1 aAjithkumar, T., G.1 aBiswas, Kaushik1 aAnnapurna, K.  uhttps://library.ncl.res.in/content/structural-elucidation-nasicon-na3al2p3o12-based-glass-electrolyte-materials-effective02511nas a2200253   4500008004100000022001400041245014300055210006900198260000900267300001100276490000800287520162800295653003201923653001201955653002801967653002001995100001602015700002302031700001802054700002302072700001302095700001702108856013202125       2021                        eng d  a0022-309300aSynthesis and characterization of LAGP-glass-ceramics-based composite solid polymer electrolyte for solid-state Li-ion battery application0 aSynthesis and characterization of LAGPglassceramicsbased composi  cAPR   a1206540 v5583 a<p>Solid State Electrolytes (SSEs) are the future alternatives of the present conventional liquid electrolytes in terms of safety, high temperature stability and also good electrochemical performance. Glass (G), based on Lithium Aluminium Germanium Phosphate (LAGP) was prepared and converted into glass-ceramics (GC) by optimized heating schedule. The crystalline LAGP has Na Super Ionic CONductor (NASICON) type unit cell where the lithium ions hop between two different positions providing long range ionic motion. To improve the inter electrode surface resistance and cell performance, Composite Solid Electrolyte (CSE) was prepared with poly (vinylidene fluoride-co-hexaflurophoaphate) (P(VDF-HFP)), 20wt% LAGP, Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 1-Ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMITFSI). X-ray diffraction patterns confirm the formation of the NASICON phase in LAGP GC and the amorphous nature of the CSE. NMR studies confirm formation of the Ge/AlO6 octahedra and PO4 tetrahedra inside the crystal. 7Li NMR also confirmed two different Lithium sites in LAGP crystal. The ionic conductivity values of CSE and LAGP GC are (4.49 +/- 0.31) x 10(-3)Scm(-1) and (2.70 +/- 0.04) x 10(-4)Scm(-1), respectively. The thermal stability of the prepared CSE is tested upto 315 degrees C without any degradation. Two cells (Cell-I &amp; Cell-II) were fabricated using the LAGP GC and CSE respectively. Cell-II shows the specific discharge capacity of 151mAhg1 at 50th cycle which is higher as compared to Cell-I (129mAhg(-1)) when tested at the C-rate of 0.05 degrees C.</p>
10aLithium germanium phosphate10aNASICON10aSolid state electrolyte10aSolid state NMR1 aDas, Anurup1 aGoswami, Madhumita1 aIllath, Kavya1 aAjithkumar, T., G.1 aArya, A.1 aKrishnan, M.  uhttps://library.ncl.res.in/content/synthesis-and-characterization-lagp-glass-ceramics-based-composite-solid-polymer-electrolyte