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PVA/CuI polymer composite samples have been prepared and subjected to characterizations using FT-IR spectroscopy, DSC analysis, ac spectroscopy and dc conduction. The FT-IR spectral analysis shows remarkable variation of the absorption peak positions whereas DSC illustrates a little decrease of both glass transition temperature, Tg, and crystallization fraction, χ, with increasing CuI concentration. An increase of dc conductivity for PVA/CuI nano composite by increasing CuI concentration is recoded up to 15 wt%, besides it obeys Arhenuis plot with an activation energy in the range 0.54–1.32 eV. The frequency dependence of ac conductivity showed power law with an exponent 0.33 < s < 0.69 which predicts hopping conduction mechanism. The frequency dependence of both dielectric permittivity and dielectric loss obeys Debye dispersion relations in wide range of temperatures and frequency. Significant values of dipole relaxation time obtained which are thermally activated with activation energies in the range 0.33–0.87 eV. A significant value of hopping distance in the range 3.4–1.2 nm is estimated in agreement with the value of Bohr radius of the exciton.

With a low cost and high volumetric capacity, rechargeable magnesium batteries (RMBs) have emerged as promising candidates for post-lithium ion batteries. The kinetically sluggish Mg 2+ insertion/ extraction in the host lattice and the anode/electrolyte incompatibility render the battery irreversible in some instances and restrict the commercial applications. In this work, we replace the conventional electrolyte with a dual layer of liquid and polymer electrolyte onto the cathode and anode, respectively, and investigate the structural, electrical, and electrochemical properties. It exhibits a remarkable Mg-ion conductivity up to 4.62 × 10 −4 S cm −1 at 55 °C, a high transfer number (t Mg 2+ = 0.74), low overpotential, and relatively stable Mg stripping and plating during the initial cycles. Furthermore, this work uses an unconventional electrode, BaTiO 3 (BTO), to demonstrate the performance of Mg batteries and track the structural and electrochemical changes. The quasi-solid-state Mg batteries fabricated with premagnesiation and thermally treated BTO cathode materials show good electrochemical performance. The approaches herein may provide new directions for exploiting high-performance Mg batteries through the perovskite structure cathode and functional dual electrolyte.

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The magnesium–sulfur (MgS) battery is a promising alternative to the post-lithium battery because of its low-cost construction, eco-friendliness, high theoretical energy density, and safety. However, the lack of simple compatible electrolytes, self-discharge, polysulfide shuttle effect, and the slow conversion reaction pathway still limit its practical applications. Here, we propose a simple halogen-free electrolyte (HFE) based on Mg­(NO3)2 dissolved in the cosolvent of acetonitrile (ACN) and tetraethylene glycol dimethyl (G4) that applies to a Mg/S full cell. The as-prepared Mg-ion electrolyte exhibits efficient Mg plating/stripping performance, high anodic stability (vs Mg/Mg2+), and a high ionic conductivity of ∼10–4 S cm–1 at 313 K. Chronoamperometry (CA), scanning electron microscopy, and energy-dispersive spectroscopy examinations report that the HFE supports flat, dendrite-free, and translucent Mg deposits. Polymer layer interface (PLI)-based polyvinylidene fluoride (PVDF) and Mg­(O3SCF3)2 have been designed to isolate the surface of the Mg anode from the liquid electrolyte. A sulfur cathode with the anchoring materials of silicon carbide and barium titanate-based material has been designed and characterized. The Mg/S battery has been constructed with an initial discharge capacity of up to 1200 mAh g–1, and it has retained a reversible capacity at 100 mAh g–1 after 10 cycles. This study offers a pivotal role in designing a promising HFE candidate for a high-performance MgS battery.