The design of high-entropy O3-type layered oxides has been considered as an effective method for suppressing multiple phase transitions during cycling and improving stability. Herein, a series of high entropy layered oxides (HEOs) with different Mg:Sn ratios are investigated. It is found that the structural stability and electrochemical performance of these HEOs can be optimized by varying the Mg to Sn ratio. A lower Mg content is conducive to the formation of a single-phase HEO. An optimized HEO composition (namely NaNi0.1Co0.2Mn0.2Fe0.2Cu0.1Mg0.04Sn0.16O2) exhibits high specific capacity (137.3 mAh g−1 at 0.1C) and good rate capability (~100 mAh g−1 at 1C). The cycling performance (capacity retention of ~87 % after 200 cycles at 0.5C) is also comparable to the reported O3-type HEOs. Such good performance can be attributed to its good redox activity, low interfacial impedance, higher Na+ diffusion coefficient (2.26 × 10−11 cm2 s−1) and reversible O3-P3 phase transition. © 2024 Elsevier Ltd

An Ru@TiO2 sandwich structure of TiO2|Ru|TiO2 is developed via a novel synthesis method by etching two-dimensional K2Ti2O5 in a salicylic acid solution and further inserting Ru nanodots between anatase TiO2 layers. In this sandwich structure, Ru nanodots are in close contact with anatase TiO2 layers and dispersed more on the edge, which promotes electron transfer and limits the aggregation of Ru nanoparticles. The orientation distribution of the Ru@TiO2 sandwich obtained with processing electron diffraction (PED) indicates that {002} crystal planes are dominant for Ru nanodots, which exhibit high HER activity. Applied to the hydrogen evolution reaction (HER), a 2.54 wt% Ru@TiO2 sandwich not only shows comparable activity to 20 wt% Pt/C but also exhibits higher current densities at low potentials. Meanwhile, the mass and price activities of Ru@TiO2 sandwich are 13 and 50 times, respectively, higher than those of 20 wt% Pt/C. This report provides a novel approach to designing the morphology of hetero-structured catalysts.

氟化铁由于Fe–F键的高离子性和大的理论容量,是发展大容量锂/钠电池的关键候选正极材料.开发其新型矿物相是改善氟化铁类材料本征离子/电子导电率、减少非电化学活性组分辅助、提高其在转换反应和大尺寸离子嵌入方面活性的最有力手段,也是难点所在.本文总结了近年来通过模块化学和开框架策略探索新型结构原型的储能氟化铁的研究进展,特别针对六方钨青铜（HTB）、四方钨青铜（TTB）、烧绿石相（pyrochlore）等进行了介绍,这些成果解决了长期困扰氟基材料的导电性差、掺碳量高、储锂功率密度小、储钠能量密度低等难题.

In our previous work, we adopted the organic acids assisted sol–gel method to prepare ZrO2 aerogels. In preparation process, we found the organic acids with two carboxyl groups and one side group including –OH, –NH2, and –SH were prerequisite to form wet gels. Furthermore, the citric acid with three carboxyl groups and one hydroxyl group was also successfully to form wet gels. Therefore, we speculated that the organic acids required to possess at least two carboxyl groups and one side group to form wet gels. In this work, different organic reagents including acetic acid (AA), oxalic acid (OA), lactic acid (LA), edetic acid (EDTA), butanediol (BD), glycerol (GA), citric acid (CA), L-malic acid (LMA) and L-tartaric acid (LTA) were adopted as gel accelerators to verify our assumption. A series of ZrO2 aerogels were successfully synthesized using ZrOCl2·8H2O as zirconium precursor, and LMA or LTA as the gel initiators by the sol–gel method. It was found that the gelation time of LTA as gelator was shorted than that of LMA in the same condition. When LTA as an gelator, the tetragonal phase can keep until 1000 °C, while for LMA, the tetragonal phase can keep at 800 °C. After supercritical fluid drying (SCFD), ZrO2 aerogel with high surface area of over 339 m2·g−1 and large pore volume of over 0.92 cm3·g−1 can be obtained. Graphical Abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Garnet-type Ta-doped Li7La3Zr2O12 (LLZTO) electrolyte suffers from unstable chemical passivation under air exposure, responsible for the poor interfacial wettability and conductivity with Li metal. Instead of conventional methods to remove surface contaminants by mechanical polishing, acid etching and high temperature reduction, herein we propose a simple strategy of interfacial gas release and detergency to smartly convert Li2CO3 passivation layer into ion-conductive Li3PO4 domains at mild temperature (∼200 ℃). The in-situ formation of PH3 vapor and its phosphorization enables a dramatic decrease of Li/garnet interfacial resistance down to 2 Ω cm2 at room temperature (RT). The improved interfacial wettability and conductivity endow the symmetric cells with ultra-stable galvanostatic cycling over 1500 h and high critical current density of 2.6 mA/cm2. The high coulombic efficiency of Li plating enables a high reversibility of solid-state NCM811/Li cells even under a low N/P ratio (∼4) and high cut-off voltage of 4.5 V at RT. The prototype of fluoride-garnet solid-state batteries are successfully driven as rechargeable system (rather than widely known primary battery) with high conversion capacity (400 ∼ 500 mAh/g) and high-rate performance (251.2 mAh/g at 3 C). This interface infiltration-detergency approach provides a practical solution to the achievement of high-energy solid-state Li metal batteries. © 2022 Elsevier Ltd

Biomass-derived porous carbons have received an extensive importance as effective electrode materials owing to their abundance and low cost. The unique porous architectures and large specific surface areas of biomass are beneficial for manipulating the charge storage performance of assembled supercapacitor devices. Here, we demonstrate nitrogen and phosphorus self-doped hierarchical porous carbon (N/P-HPC) derived from yeast (Y) and phytic acid (PA) precursors via freeze-drying-assisted esterification reaction and pyrolysis treatment. The supercapacitive performance and charge storage capability of N/P-HPC were regulated by optimizing the Y/PA composition and controlling the carbonization temperature. Accordingly, the resultant N/P-HPC-Y:PA(2:1)-800 (fabricated with an optimized Y:PA ratio of 2:1 and carbonized at 800 degrees C) reveals a high specific surface area of 978 m2 g-1 and a large pore volume of 0.592 cm3 g-1. As an electrode material, N/P-HPC-Y:PA(2:1)-800 delivers a high specific capacitance of 432 F g-1 at a current density of 1 A g-1 and can sufficiently retain about 250 F g-1 at 20 A g-1 under a three-electrode cell configuration in 1.0 M H2SO4 electrolyte. Moreover, the as assembled symmetric supercapacitor device operated with the N/P-HPC-Y:PA(2:1)-800 as both positive and negative electrode material exhibits an energy density of 13.6 Wh kg- 1 at a power density of 500 W kg -1. Even at a larger current density of 20 A g-1, the device maintains an energy density of 10.4 Wh kg- 1 and a maximum power density of 10 kW kg -1. The constructed device displays a large capacitance retention of 93.3% after 10 000 charge/discharge times at a higher current density of 10 A g-1, manifesting the enhanced cycling stability.

Heterostructure construction, especially for anodes, is an effective strategy to promote electron transfer and improve surface reaction dynamics, thus achieving high performance in lithium-ion batteries. Herein, in situ partial conversion of metal sulfide to oxide with high lattice match is utilized to engineer a ZnO/ZnS heterostructure. The mosaic ZnO/ZnS heterostructure with abundant interfaces is activated into homogeneous zinc oxysulfide with size optimization during cycling, which delivers 920 mA h g(-1) after 1300 cycles even at 2 A g(-1). A pouch-type full cell (LiCoO2||ZnO/ZnS) is assembled and maintains over 85% of its initial capacity after 300 cycles at 2C, confirming its potential practicability. Theoretical calculations predict that, combined with LiZn nanodots, the Li2O/Li2S matrix is endowed with more Li anchoring sites and higher Li adsorption energy. Therefore, the interfacial charge redistribution is modified to contribute high interfacial Li storage. The reasonable interfacial engineering by designing a mosaic heterostructure breaks new grounds for the design of large-capacity and high-reversibility conversion-alloying-type anodes.

Manipulating the structure of electroactive materials with hierarchical frameworks can boost the electrochemical properties. The soaring fidelity of mixed nanostructured materials in electrochemistry verifies their candidature as appropriate electrodes for sustainable energy storage and conversion devices. Herein, we present facile and economical techniques to develop three-dimensional (3D) hierarchical nanoframes-like sulfurized nickel aluminum (sulfurized NiAl) as a positive electrode material and ternary bismuth cerium sulfide (Bi-Ce-S) as the negative electrode material for constructing an aqueous asymmetric supercapacitor system. These hierarchical architectures with well-developed pores and hollow spaces can capitalize the surface-to-volume ratio and maximize the contact area between the active material and electrolyte, therefore immensely reduce the ion penetration distances and promote the electron transport rates. Tuning the conductivity of electrode materials affords rich contact sites and integrates the features of all components, thus resulting in better electrochemical enhancements. As expected, sulfurized NiAl nanosheet arrays with unique porous architectures exhibit a good electrochemical performance with commendable specific capacitance of 1230.6 F g(-1)- at 1 A g(-1) current density and stable rate capability (69.8% up to 20 A g(-1)). In addition, the obtained Bi-Ce-S hybrid provides a high specific capacitance (411.7 F g(-1) at 1 A g(-1)) with 92.2% capacitance retention even after 4000 cycles. An asymmetric supercapacitor (ASC) device is established with the designed composites, which realizes a high energy density of 38.5 Wh kg(-1) at a power density of 750 W kg(-1) and reveals an enhanced cycle stability (80.6% retention after 8000 GCD times).

The lithium metal batteries (LMBs) using lithium metal as the anode have attracted widespread attention as the next-generation high energy batteries. However, during the cycling process, the continuous chain side reactions between lithium and carbonate electrolyte and the growth of lithium dendrites would cause the failure of the batteries. In this paper, we propose that a metal carbodiimide (Ag2NCN)-derived organic-inorganic interface protective layer (MIPL) can effectively protect the lithium anode in practical LMBs. The MIPL has a double-layer structure with an outer layer of organic lithium carbodiimide (Li2NCN) and an inner layer of inorganic silver. The outer Li2NCN layer can stably adsorb ethylene carbonate molecules, promote the desolvation of lithium ions, and prevent the chain side reaction between lithium and carbonate electrolyte. Meanwhile, the inner silver layer promotes lithium metal nucleation, resulting in dendrite-free growth of lithium. Due to the advantages of MIPL, the practical MIPL-Li//NCA pouch cell with high energy of 357 Wh kg(-1) (861 Wh L-1) has a stable lifespan for more than 100 cycles. This work not only provides a double-layer structure based on interface modification to protect Li anode, but also points out the possibility of carbodiimide compounds used in the field of LMBs.