ZnO, aside from TiO2, has been considered as a promising material for purification and disinfection of water and air, and remediation of hazardous waste, owing to its high activity, environment-friendly feature and lower cost. However, their poor visible light utilization greatly limited their practical applications. Herein, we demonstrate the fabrication of different aspect ratios of the ZnO nanorods with surface defects by mechanical-assisted thermal decomposition method. The experiments revealed that ZnO nanorods with higher aspect ratio and surface defects show significantly higher photocatalytic performances.

Phase transformation reactions including alloying or conversion ones have often been utilized recently to improve the capacity performance of Na-ion battery anodes. However, they tend to induce larger volume change and more sluggish Na-ion transport at multiphase solid interfaces than for Li-ion batteries, leading to inefficiency of mixed conductive networks and thus degradation of reversibility, polarization, or rate performance. In this work, we use a structurally stable Li4Ti5O12 spinel thin film as insertion-type model material to investigate its intrinsic Na-ion transport kinetics and coupled pseudocapacitive charging. It is found that the latter effect is remarkably activated by the nanocrystalline microstructure full of defect-rich surface, which can simultaneously promote Na-ion and electron accessibility to the surface/subsurface. It is proposed that the extra pseudocapacitive charge storage is a potential solution to the high-capacity and high-rate insertion anodes without trade-off of serious phase transformation or structural collapse. Therefore, a highly reversible charge capacity of 225 mAh g–1 (exceeding the theoretical value 175 mAh g–1 based on insertion reaction) at 1C is achievable.

Conversion reaction enables Li/garnet interface to construct a kinetically stable interfacial layer for the homogeneous ions transport in all-solid-batteries.

The development of cost-effective catalysts to replace noble metal is attracting increasing interests in many fields of catalysis and energy, and intensive efforts are focused on the integration of transition-metal sites in carbon as noble-metal-free candidates. Recently, the discovery of single-atom dispersed catalyst (SAC) provides a new frontier in heterogeneous catalysis. However, the electrocatalytic application of SAC is still subject to several theoretical and experimental limitations. Further advances depend on a better design of SAC through optimizing its interaction with adsorbates during catalysis. Here, distinctive from previous studies, favorable 3d electronic occupation and enhanced metal-adsorbates interactions in single-atom centers via the construction of nonplanar coordination is achieved, which is confirmed by advanced X-ray spectroscopic and electrochemical studies. The as-designed atomically dispersed cobalt sites within nonplanar coordination show significantly improved catalytic activity and selectivity toward the oxygen reduction reaction, approaching the benchmark Pt-based catalysts. More importantly, the illustration of the active sites in SAC indicates metal-natured catalytic sites and a media-dependent catalytic pathway. Achieving structural and electronic engineering on SAC that promotes its catalytic performances provides a paradigm to bridge the gap between single-atom catalysts design and electrocatalytic applications.

All-solid-state lithium-ion battery is considered to be one of the most promising next-generation battery technologies. Understanding the interfacial evolution of a solid electrolyte and a cathode electrode during mixing and sintering is of great importance and can provide guidance to avoid forming unwanted compounds and decrease the interfacial resistance. In this work, chemical compatibilities are investigated between a Ta-doped Li 7 La 3 Zr 2 O 12 (LLZO) solid electrolyte and major commercial metal-oxide cathodes LiCoO 2 (LCO) and Li(NiCoMn) 1/3 O 2 (NCM) through ballmilling and cosintering processes. As revealed by X-ray absorption spectroscopy and transmission electron microscopy, LLZO spontaneously covers the majority of the large LCO and NCM particles with a thickness of ∼100 nm after ball milling. The thickness of LLZO layer on these cathodes decreases to about 10 nm after cosintering at 873 K, and an interfacial layer of approximately 3 nm is observed for NCM/LLZO. LCO shows a higher thermal stability than NCM. Density functional theory (DFT)-based simulations and electrochemical measurements suggest Ni−La and Ni−Li exchange could happen at the NCM/LLZO interface and Li can diffuse from the interface into NCM to occupy the Ni vacancy at high temperature. The Li depletion layer after diffusion at the interface induces the decomposition of LLZO and the formation of La 2 Zr 2 O 7 and LaNiO 3 interfacial layer.

Layered doubled hydroxides (LDHs) have aroused much attention in energy storage for their exchangeable anions and tunable interlayer spacing. However, poor electrical conductivity and aggregation of flakes cause huge volume changes and reduce accessible active sites, leading to inferior cycle stability and rate performance. Hence, a NiFe-LDH/Ti3C2 MXene hybrid with uniformly distributed NiFe-LDH nanoflakes decorated on MXene nanosheets through a simple hydrothermal reaction is prepared. Due to the synergism between the Ti3C2 MXene conductive frameworks and NiFe-LDH, NiFe-LDH/ Ti3C2 MXene shows a superior electrochemical property for lithium storage. Its reversible capacity is 898.9 mAh g–1 at 0.1 A g–1, and even at 1 A g–1, it still has 726.1 mAh g–1, without capacity reduction in lithium-ion half-cells. In addition, the corresponding lithium-ion capacitor shows a higher energy density and power density, showing huge application prospect in lithium storage.

The structure of polyanionic materials is conventionally known to be free of transition metal migration and structurally stable when storing/releasing sodium ions. Herein, the observation of enhanced cycling stability of a typical polyanionic cathode, Na3VCr(PO4)3 (NVCP) at lower temperature (−15 °C vs 30 °C), triggers the exploration of its structural origins with a surprising finding that the migratable nature of vanadium in NVCP leads to detrimental structural degradation of the polyanionic host upon cycling. The correlation between long range and short range structural change associated with this atomic migration is established via a strong combination of various in situ/ex situ characterization tools, revealing the essential V–to–Na1 site migration. Such transition metal migration is effectively suppressed when V atoms are pinned to their original position in the lattice by lowering the temperature. More importantly and practically, a room temperature‐based deep sodiation strategy is further developed to recover the structure. This work challenges the long‐standing assumption of the stability of the polyanionic framework structure and calls for urgent attention to the structural understanding of the NVCP system as well as strategy development for property enhancement.

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