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Developing a rational design for oxide‐based solid electrolytes to promote ionic conductivity, decrease the sintering temperature, and improve stability with metallic Li is challenging. Herein, core–shell‐structured Li1.3Al0.3Ti1.7(PO4)3@Li2O–2B2O3 (LATP–LBO) microspheres are prepared using one‐pot spray pyrolysis. Phase separation between crystalline LATP and amorphous LBO leads to the formation of a core–shell‐structured LATP–LBO composite. On the surface of LATP–LBO composite, the LBO shell forms a liquid phase during low‐temperature sintering, thereby enhancing the densification. The LBO shell also decreases the grain boundary resistance by forming a thin layer between the LATP grains, thus increasing the total ionic conductivity. Because Li‐ion conductive LBO occupies the grain boundary, a total ionic conductivity of 1.519 × 10−4 S cm−1 is achieved at a low sintering temperature of 700 °C. Additionally, the LBO shell provides good electrochemical stability for LATP with metallic Li. The improved ionic conductivity and chemical stability can be attributed to the synergistic advantages of the spherical morphology, core–shell structure, and uniformity of LBO. [ABSTRACT FROM AUTHOR]

The development of efficient bifunctional electrocatalysts is important for improving the electrochemical performance of Li–O2 batteries (LOBs). Herein, porous graphitized carbon hollow nanospheres (denoted as PGHs) with nano-punched holes containing suitable defects and minimal amorphous carbon content are developed as highly efficient substrates for loading metal-compound electrocatalysts. For preparing PGH, Fe metal is employed as a nanocatalyst to convert amorphous carbon to graphitic carbon with high electrical conductivity, and nano-punched holes are formed via the selective combustion of amorphous carbon and elimination of Fe metal. PGH possessing nano-punched holes and meso-/macropores facilitates the diffusion of dissolved oxygen and provides sufficient space to store the Li2O2 generated during the discharge process. Compared to hollow porous amorphous carbon nanospheres (denoted as PAHs), PGH exhibits a lower overpotential and higher specific capacity. To hybridize with metal selenide, NiFe selenide nanoparticles are uniformly loaded onto PGH (PGH/NiFeSe) via simple impregnation and subsequent selenization. By introducing NiFe selenide, the LOB performances of the hybrid electrode are enhanced compared to those of an electrode comprising PGHs and PAHs. Due to the metal selenide nanoparticles and suitable porous structure of the carbon substrate, PGH/NiFeSe exhibits improved electrochemical performance in LOBs, including reduced polarization, high specific discharge/charge capacity, and stable cycle performance. [ABSTRACT FROM AUTHOR]

Surface coating approaches for silicon (Si) have demonstrated potential for use as anodes in lithium-ion batteries (LIBs) to address the large volume change and low conductivity of Si. However, the practical application of these approaches remains a challenge because they do not effectively accommodate the pulverization of Si during cycling or require complex processes. Herein, Si-embedded titanium oxynitride (Si-TiON) was proposed and successfully fabricated using a spray-drying process. TiON can be uniformly coated on the Si surface via self-assembly, which can enhance the Si utilization and electrode stability. This is because TiON exhibits high mechanical strength and electrical conductivity, allowing it to act as a rigid and electrically conductive matrix. As a result, the Si-TiON electrodes delivered an initial reversible capacity of 1663 mA h g−1 with remarkably enhanced capacity retention and rate performance. [ABSTRACT FROM AUTHOR]