Ionic conductivity and interfacial properties of nanochitin-incorporated polyethylene oxide–LiN(C2F5SO2)2 polymer electrolytes

Nanocomposite polymer electrolytes (NCPE) composed of poly(ethylene oxide) and nanochitin for different concentrations of LiN(C2F5SO2)2 (LiBETI) were prepared by a completely dry, solvent-free procedure using a hot press. The thermal stability of NCPE membranes was investigated by DSC and TG-DTA. The membraneswere subjected to SEM, ionic conductivity and FTIR analysis. Li/NCPE/Li symmetric cellswere assembled and the variation of interfacial resistance as a function of time was also measured. The surface chemistry of lithium electrodes in contact with NCPE revealed the formation of Li–O–C and LiN compounds. LiFePO4/NCPE/Li cell was assembled and the cycling profile showed a well-defined and reproducible shape of the voltage curves thus indicating a good cycling behavior of the cell at 60 ◦C

Composite Polymer Electrolytes Encompassing Metal Organic Frame Works: A New Strategy for All-Solid-State Lithium Batteries

Magnesium-benzene tricarboxylate metal organic framework (Mg-BTC MOF)-incorporated composite polymer electrolytes (CPE) composed of poly(ethylene oxide) (PEO) and lithium bistrifluoromethane sulfonylimide (LiTFSI) were prepared by a simple hot-press technique. The incorporation of Mg-BTC MOF in the polymeric matrix has significantly enhanced the ionic conductivity of CPE up to two orders magnitudes even at 0 °C. It also improved the thermal stability, compatibility, and elongation-at-break of the polymeric membrane. The all-solid-state lithium polymer cell composed of Li/ CPE/LiFePO4 has delivered a stable discharge capacity of 110 mAh g−1 at 70 °C with a current rate of 1-C, which is higher than that of those reported earlier. The appealing properties such as high ionic conductivity, better compatibility, and stable cycling qualify this membrane as electrolyte for all-solid-state lithium batteries for elevated temperature application

Chitin-Incorporated Poly(ethylene oxide)-Based Nanocomposite Electrolytes for Lithium Batteries

Nanocomposite polymer electrolytes (NCPE), with different proportions of poly(ethylene oxide)/LiClO4/ chitin were prepared by a hot press method. Nanochitin, a biopolymer, poly(�-(1f4)-N acetyl-D-glucosamine) was incorporated as a filler in poly(ethylene oxide) (PEO). The ionic conductivity of the composite polymer electrolytes was enhanced by one order upon addition of nanochitin. The lithium transference number, tLi +, was increased from 0.24 to 0.51 upon chitin addition. The membranes were subjected to scanning electron microscopy, thermogravimetric-differential thermal analysis, differential scanning calorimetry, ionic conductivity, and Fourier transform infrared (FTIR) spectroscopy analysis. The free volume Vf was probed by positron annihilation lifetime spectroscopy studies at 30 °C. Li/NCPE/Li symmetric cells were assembled, and the thickness of the solid electrolyte interface as a function of time was analyzed. This paper also describes FTIR spectroscopic studies of the interface between lithium metal and NCPE, which suggests that the surface chemistry of lithium electrodes in contact with NCPE is dominated by compounds with C-N-Li and C-O-Li bonding

Nanocellulose-laden composite polymer electrolytes for high performing lithium-sulphur batteries

In the endless search for superior and green power sources, lithium sulphur (Li-S) batteries held the promise of opening up a new era of long lasting and high energy storage systems for variety of applications. They might envisage remarkable benefits in utilising polymer electrolytes instead of liquids in terms of safety, low-cost and gravimetric/volumetric energy densities. In this work, for the first time, nanoscale microfibrillated cellulose-laden polymer systems are prepared using a thermally induced polymerisation process and tested as electrolyte separator in a Li-S rechargeable battery that contains sulphur-carbon composite based cathode. The polymer electrolyte demonstrates excellent ionic conductivity, thermal stability and most importantly stable interface towards lithium metal. While comparing our earlier report with non-aqueous liquid electrolyte, the present cell based on the abundant truly-natural cellulose-based polymer electrolyte as separator exhibits better cycling stability, higher specific capacity, superior Coulombic efficiency and rate capability at ambient conditions

Cycling profile of innovative nanochitin-incorporated poly (ethylene oxide) based electrolytes for lithium batteries

Nanochitin has been incorporated in a poly (ethylene oxide) (PEO)-LiPF6 matrix for the first time. The incorporation of chitin whiskers significantly improves the ionic conductivity, thermal stability, mechanical integrity along with the interfacial properties. The prepared membrane is also tested in a LiFePO4/CeLi cell and the galvanostatic cycling behaviour is analysed at 70 �C showing an improved specific capacity and outstanding cycling stability. The obtained results and the use of such environment friendly component would make these hybrid organic, nanochitin-based composite polymer electrolyte systems a strong contender in the field of flexible and green lithium-based power source

MgAl2SiO6-incorporated poly(ethylene oxide)-based electrolytes for all-solid-state lithium batteries

Poly(ethylene oxide) (PEO)-based composite polymer electrolytes (CPEs), comprising various concentrations of lithium hexafluorophosphate and magnesium aluminium silicate, were prepared by hot-press technique. The membranes were characterised by scanning electron microscopy, tensile and thermal analyses. It has been demonstrated that the incorporation of the ceramic filler in the polymeric matrix has significantly enhanced the ionic conductivity, thermal stability and mechanical integrity of the membrane. It also improved the interfacial properties with lithiumelectrode. Finally, an all solid-state lithium cell composed of Li/CPE/LiFePO4 has been assembled and its cycling performance was analysed at 70 °C. The cell delivered a discharge capacity of 115 mAh g−1 at 1 °C rate and is found to be higher than previous reports

Metal-organic frameworks based membrane as a permselective separator for lithium-sulfur batteries

Although lithium-sulfur batteries possess five-fold higher theoretical capacity than the state-of-the-art lithium-ion batteries, the migration of polysulfide between the electrodes remains as a problem area. In order to overcome this issue, numerous strategies have been adopted. Herein, we introduce a novel 1,3,5 benzene tricarboxylate-manganese (Mn-BTC) metal organic framework (MOF) coated-Celgard (2320) separator which acts as permselective in a Li-S cell. The Li-S cell with coated membrane exhibited higher discharge capacity than the uncoated one. The diffusion of polysulfides is successfully blocked by the separator due to the repulsive ionic forces provided by the COOe that is present in the periphery of Mn-BTC MOF which was confirmed by XPS and XRD analyse

Cycling profile of MgAl2O4-incorporated composite electrolytes composed of PEO and LiPF6 for lithium polymer batteries

Magnesium aluminate (MgAl2O4)-incorporated poly(ethylene oxide) (PEO)-lithium hexafluorophosphate (LiPF6) based composite polymer electrolyte (CPE) membranes were prepared by a hot press for the first time. The membranes were subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric (TG), differential scanning calorimetry (DSC), tensile, impedance spectroscopy, compatibility and transport number studies. The incorporation of MgAl2O4 greatly enhanced the ionic conductivity, compatibility and mechanical integrity of the polymeric membrane. Finally, an all solid state lithium cell composed of Li/CPE/LiFePO4 was assembled and its cycling profile was analyzed at 70 ◦C. The cells delivered a discharge capacity of 127 mAh g−1 at 1 C-rate with very good capacity retention up to 100 cycles which is found to be better than those reported earlier