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In the present study, polycrystalline (1 − y) [Ba0.85Ca0.15Zr0.1Ti0.9O3] (BCZTO) + (y) [Ni0.92Co0.03Mn0.05Cu0.05Fe1.95−xAlxO4] (NCMCFAlxO) (where x = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and y = 0.5) composites were synthesized via solid state reaction route. The samples were characterized through the standard techniques. X-ray diffraction (XRD) analysis revealed the successful formation of the BCZTO-NCMCFAlxO composites without any extra phases and diffusion. The lattice parameter of BCZTO and NCMCFAlxO decreases as the concentration of Al3+ increases. SEM analysis reveals that the microstructure exhibits nonuniform grain size distribution with Al3+ concentration. The dispersion of dielectric constant is well consistent with Maxwell-Wagner interfacial polarization and the dielectric constant decreases as the concentration of Al3+ ions increases due to the difference of ionic radii. The electrical conductivity is due to the small polaron hopping according to Austin-Mott model. The decrement in saturation magnetization with increasing Al3+ concentration because exchange interactions is weakened through the substitution of Fe3+ by Al3+ ions. Permeability decreases with Al3+ concentration and exhibits good frequency stability over the entire measured frequency domain. The magnetoelectric coupling coefficient decreases as the concentration of Al3+ increases at both sintering temperatures which is due to the variation of grain size. The maximum magnetoelectric voltage coefficient of 0.72 V Oe−1 cm−1 was obtained for the pristine composite at 1373 K. [ABSTRACT FROM AUTHOR]

A dual-layer interphase that consists of an in-situ-formed lithium carboxylate organic layer and a thin BF 3 -doped monolayer Ti 3 C 2 MXene on Li metal is reported. The honeycomb-structured organic layer increases the wetting of electrolyte, leading to a thin solid electrolyte interface (SEI). While the BF 3 -doped monolayer MXene provides abundant active sites for lithium homogeneous nucleation and growth, resulting in about 50% reduced thickness of inorganic-rich components among the SEI layer. A low overpotential of less than 30 mV over 1000 h cycling in symmetric cells is received. The functional BF 3  groups, along with the excellent electronic conductivity and smooth surface of the MXene, greatly reduce the lithium plating/stripping energy barrier, enabling a dendrite-free lithium-metal anode. The battery with this dual-layer coated lithium metal as the anode displays greatly improved electrochemical performance. A high capacity-retention of 175.4 mAh g -1 at 1.0 C is achieved after 350 cycles. In a pouch cell with a capacity of 475 mAh, the battery still exhibits a high discharge capacity of 165.6 mAh g -1 with a capacity retention of 90.2% after 200 cycles. In contrast to the fast capacity decay of pure Li metal, the battery using NCA as the cathode also displays excellent capacity retention in both coin and pouch cells. The dual-layer modified surface provides an effective approach in stabilizing the Li-metal anode., (© 2022 Wiley-VCH GmbH.)