Santosh Kumar

Uncontrollable Zn dendrite formations and parasitic side reactions on Zn electrodes induce poor cycling stability and safety issues, preventing the large-scale commercialization of Zn-ion batteries. Herein, to achieve uniform Zn deposition and suppress side reactions, an electrospun ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) copolymer, a P(VDF-TrFE) nanofiber layer, is introduced as an artificial solid–electrolyte interface on a Cu substrate acting as a current collector. The aligned molecular structure of β-P(VDF-TrFE) can effectively suppress localized current density on the Cu surface, lead to uniform Zn deposition, and suppress side reactions by preventing direct contact between electrodes and aqueous electrolytes. The half-cell configuration formed by the newly fabricated electrode can achieve an average coulombic efficiency of 99.2% over 300 cycles without short-circuiting at a current density of 1 mA cm⁻² and areal capacity of 1 mAh cm⁻². Stable cycling stability is also maintained for 200 cycles at a current density of 0.5 A g⁻¹ in a full-cell test using MnO₂ as a cathode.

Uncontrollable Zn dendrite formations and parasitic side reactions on Zn electrodes induce poor cycling stability and safety issues, preventing the large-scale commercialization of Zn-ion batteries. Herein, to achieve uniform Zn deposition and suppress side reactions, an electrospun ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) copolymer, a [P(VDF-TrFE)] nanofiber layer, is introduced as an artificial solid-electrolyte interface on a Cu substrate acting as a current collector. The aligned molecular structure of β-P(VDF-TrFE) can effectively suppress localized current density on the Cu surface, lead to uniform Zn deposition, and suppress side reactions by preventing direct contact between electrodes and aqueous electrolytes. The half-cell configuration formed by the newly fabricated electrode can achieve an average coulombic efficiency of 99.2% over 300 cycles without short circuiting at a current density of 1 mA cm-2 and areal capacity of 1 mAh cm-2. Stable cycling stability is also maintained for 200 cycles at a current density of 0.5 A g-1 in a full-cell test using MnO2 as a cathode.

Silica nanoparticles bearing hyperbranched polyglycidol (hbP) grafts are synthesized and blended with poly(ethylene oxide) (PEO) for the fabrication of composite solid polymer electrolytes (SPEs) for enhancing Li‐ion conductivity. Different batches of hbPs are prepared, namely, the 5th, 6th, and 7th with increasing molecular weights using cationic ring‐opening polymerization and grafted the hbPs onto the silica nanoparticles using quaternization reaction. The effect of end functionalization of hbP‐grafted silica nanoparticles with a nitrile functional group (CN–hbP–SiO₂) on the ionic conductivity of the blends with PEO is further studied. High dipole moments indicate polar nature of nitriles and show high dielectric constants. Among all the hbPs, the 6th‐batch CN–hbP–SiO₂ nanoparticles exhibit better ionic conductivity on blending with PEO showing ionic conductivity of 2.3 × 10⁻³ S cm⁻¹ at 80 °C. The blends show electrochemical stability up to 4.5 V versus lithium metal.

Synthesis of a two-dimensional (2D) highly crystalline composite, P(Py:BPDSA:Py)-GO, from the growth of a close-packed polymer crystal, P(Py:BPDSA:Py), on graphene oxide (GO) sheets via in situ polymerization of two-monomer-connected precursors (TMCPs, Py:BPDSA:Py), in which two pyrrole (Py) molecules are linked through a connector (4,4′-biphenyldisulfonic acid) (BPDSA), is reported. When the TMCP is polymerized on GO, it leads to an exceptionally ordered structure determined by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) studies. X-ray crystallography of the composite shows crystalline peaks with d spacings in the [100] direction. Transmission electron microscopy (TEM) analysis indicates that the composite has a face-centered cubic (FCC) crystal structure. Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) show that this composite with a well-defined nanostructure was successfully synthesized. Nitrogen adsorption–desorption isotherms show that this composite, P(Py:BPDSA:Py)-GO, has an improved specific surface area (71 m² g⁻¹) compared to that of P(Py:BPDSA:Py) (3.1 m² g⁻¹). The electrochemical properties of the composite studied by cyclic voltammetry indicates a specific capacitance of 480 F g⁻¹ without an additional conducting material such as carbon black, suggesting its use as a pseudocapacitor.