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The evolution of inorganic solid electrolytes has revolutionized the field of sustainable organic cathode materials, particularly by addressing the dissolution problems in traditional liquid electrolytes. However, current sulfide‐based all‐solid‐state lithium‐organic batteries still face challenges such as high working temperatures, high costs, and low voltages. Here, we design an all‐solid‐state lithium battery based on a cost‐effective organic cathode material phenanthrenequinone (PQ) and a halide solid electrolyte Li2ZrCl6. Thanks to the good compatibility between PQ and Li2ZrCl6, the PQ cathode achieved a high specific capacity of 248 mAh g−1 (96 % of the theoretical capacity), a high average discharge voltage of 2.74 V (vs. Li+/Li), and a good capacity retention of 95 % after 100 cycles at room temperature (25 °C). Furthermore, the interactions between the high‐voltage carbonyl PQ cathode and both sulfide and halide solid electrolytes, as well as the redox mechanism of the PQ cathode in all‐solid‐state batteries, were carefully studied by a variety of advanced characterizations. We believe such a design and the corresponding investigations into the underlying chemistry give insights for the further development of practical all‐solid‐state lithium‐organic batteries. [ABSTRACT FROM AUTHOR]

The flexible free‐standing cathodes with high energy density have been challenging toward wearable sodium‐ion batteries (SIBs). Herein, Na5V12O32 nanobelts (NVO‐NBs)‐based heterostructure is fabricated with boosting the sodium‐ion kinetic characteristics to address the challenges. In the heterostructure, the controllable VOC bonds are generated at the interface originating from the chemical conversion of functional groups of the reduced graphene oxides (rGOs) with VO bonding of NVO through interfacial electronic interactions. The interfacial synergistic between the brilliant bonding properties and the inherent formation of a stress field at the heterointerface motivated by work function difference can reduce the Na+ diffusion barrier, facilitate charge transfer, hence accelerates reaction kinetics and electron/ion transport, as well as modifying the electronic structure to realize a cherished adsorption energy of Na+. Therefore, the optimized NVO‐NBs‐based heterostructure exhibits exceptional rate capability (213 mAh g−1 at 0.2 C with 100 mAh g−1 at 10 C) and ultralong cycling stability (95.4%, 3000 cycles at 5 C). This work demonstrates that the controllable heterostructure interface with abundant chemical bonds is an effective approach to exploit potential cathodes for rechargeable batteries. [ABSTRACT FROM AUTHOR]

High energy density and high safety are incompatible with each other in a lithium battery, which challenges today's energy storage and power applications. Ni-rich layered transition metal oxides (NMCs) have been identified as the primary cathode candidate for powering next-generation electric vehicles and have been extensively studied in the last two decades, leading to the fast growth of their market share, including both polycrystalline and single-crystal NMC cathodes. Single-crystal NMCs appear to be superior to polycrystalline NMCs, especially at low Ni content (≤60%). However, Ni-rich single-crystal NMC cathodes experience even faster capacity decay than polycrystalline NMC cathodes, rendering them unsuitable for practical application. Accordingly, this work will systematically review the attenuation mechanism of single-crystal NMCs and generate fresh insights into valuable research pathways. This perspective will provide a direction for the development of Ni-rich single-crystal NMC cathodes. [ABSTRACT FROM AUTHOR]

Nickel‐rich (Ni≥90 %) layered cathodes are critical materials for achieving higher‐energy‐density and lower‐cost next‐generation Li‐ion batteries (LIBs). However, their bulk and interface structural instabilities significantly impair their electrochemical performance, thus hindering their widespread adoption in commercial LIBs. Exploiting Ti and Mo diffusion chemistry, we report one‐step calcination to synthesize bulk‐to‐surface modified LiNi0.9Co0.09Mo0.01O2 (NCMo90) featuring a 5 nm Li2TiO3 coating on the surface, a Mo‐rich Li+/Ni2+ superlattice at the sub‐surface, and Ti‐doping in the bulk. Such a multi‐functional structure effectively maintains its structural integrity upon cycling. As a result, such NCMo90 exhibits a high initial capacity of 221 mAh g−1 at 0.1 C, excellent rate performance (184 mAh g−1 at 5 C), and high capacity retention of 94.0 % after 500 cycles. This work opens a new avenue to developing industry‐applicable Ni‐rich cathodes for next‐generation LIBs. [ABSTRACT FROM AUTHOR]

Lithium‐rich and manganese‐based oxide (LRMO) cathode materials are regarded as promising cathode materials for lithium‐ion batteries with anionic redox characteristics and higher specific energy density. However, the complex initial structure and complicated reaction mechanism of LRMO is controversial. Herein, the reaction mechanism and unusual electrochemical phenomena are reconsidered after proposing the concept of structure distribution between Li2MnO3 and LiMO2 structures. The initial structure states show different types of composition characteristics of Li2MnO3 and LiMO2, including "large and isolated distribution" and "uniformly dispersed distribution" characteristics, as summarized by multiple aberration correction scanning transmission electron microscopy observations at the atomic‐scale for cross sectional samples. Based on the density functional theory calculations, X‐ray absorption spectroscopy, and atomic‐scale observations during the different voltage states, the results accordingly suggest that the distribution characteristic is the essential cause of the unusual behavior in LRMO. It governs the reaction behavior, leading to the changes in electronic structure of O2p and TM3d, and the maintenance of layered structure, reversibility of the anionic redox, as well as, the voltage hysteresis. This work constructs the interrelationships of electrochemical behavior—distribution characteristic—reaction mechanism, contributing to the further application of LRMO materials in the electric vehicle market. [ABSTRACT FROM AUTHOR]

Insertion‐type compounds based on oxides and sulfides have been widely identified and well‐studied as cathode materials in lithium‐ion batteries. However, halides have rarely been used due to their high solubility in organic liquid electrolytes. Here, we reveal the insertion electrochemistry of VX3 (X=Cl, Br, I) by introducing a compatible halide solid‐state electrolyte with a wide electrochemical stability window. X‐ray absorption near‐edge structure analyses reveal a two‐step lithiation process and the structural transition of typical VCl3. Fast Li+ insertion/extraction in the layered VX3 active materials and favorable interface guaranteed by the compatible electrode‐electrolyte design enables high rate capability and stable operation of all‐solid‐state Li‐VX3 batteries. The findings from this study will contribute to developing intercalation insertion electrochemistry of halide materials and exploring novel electrode materials in viable energy storage systems. [ABSTRACT FROM AUTHOR]

Single‐crystalline Ni‐rich cathode (SC‐NCM) has attracted increasing interest owing to its greater capacity retention in advanced solid‐state lithium batteries (SSLBs), while suffers from severe interfacial instability during cycling. Here, via atomic layer deposition, Li3PO4 is introduced to coat SC‐NCM (L‐NCM), to suppress undesired side reaction and enhance interfacial stability. The dynamic degradation and surface regulation of SC‐NCM are investigated inside a working SSLB by in situ atomic force microscopy (AFM). We directly observe the uneven cathode electrolyte interphase (CEI) and surface defects on pristine SC‐NCM particle. Remarkably, the formed amorphous LiF‐rich CEI on L‐NCM maintains its initial structure upon cycling, and thus endows the battery with improved cycling stability and excellent rate capability. Such on‐site tracking provides deep insights into surface mechanism and structure–reactivity correlation of SC‐NCM, and thus benefits the optimizations of SSLBs. [ABSTRACT FROM AUTHOR]

Halide solid‐state batteries (SSBs) show unparalleled application potential because of their outstanding advantages, such as high ionic conductivity and good compatibility with cathodes. However, operating halide SSBs under freezing temperatures faces big challenges, and the underlying degradation mechanisms are unclear. Herein, the impact of electronic conductivity in low‐temperature halide SSBs is investigated by designing different additives in the composite cathode. It is shown that the electrochemical stability of a halide electrolyte (Li3InCl6) with additives is significantly affected by the degree of electronic conductivity as well as the ambient operational temperature. When the ambient temperatures are below freezing point, the moderate electronic conductivity in the composite cathode is beneficial toward improving the charge transfer kinetics without inducing the decomposition of Li3InCl6. The electrode materials (LiCoO2 cathode and Li3InCl6 electrolytes) show excellent structural and interfacial stability during electrochemical reactions, resulting in a competitive performance at low temperatures. Stable long‐term cycling performance with a capacity retention of 89.2% after 300 cycles is achieved along with a C‐rate capacity of 77.6 mAh g–1 (0.6 C) at −10 °C. This in‐depth study investigates the role of electronic conductivity, which opens the door to future research on low‐temperature SSBs. [ABSTRACT FROM AUTHOR]

Numerous efforts are made to improve the reversible capacity and long‐term cycling stability of Li‐S cathodes. However, they are susceptible to irreversible capacity loss during cycling owing to shuttling effects and poor Li+ transport under high sulfur loading. Herein, a physically and chemically enhanced lithium sulfur cathode is proposed to address these challenges. Additive manufacturing is used to construct numerous microchannels within high sulfur loading cathodes, which enables desirable deposition mechanisms of lithium polysulfides and improves Li+ and e‐ transport. Concurrently, cobalt sulfide is incorporated into the cathode composition and demonstrates strong adsorption behavior toward lithium polysulfides during cycling. As a result, excellent electrochemical performance is obtained by the design of a physically and chemically enhanced lithium sulfur cathode. The reported electrode, with a sulfur loading of 8 mg cm‐2, delivers an initial capacity of 1118.8 mA h g‐1 and a reversible capacity of 771.7 mA h g‐1 after 150 cycles at a current density of 3 mA cm‐2. This work demonstrates that a chemically enhanced sulfur cathode, manufactured through additive manufacturing, is a viable pathway to achieve high‐performance Li‐S batteries. [ABSTRACT FROM AUTHOR]

Residual sulfate (SO42−) in precursor Ni0.8Co0.15Mn0.05(OH)2 (pre‐NCM) is commonly regarded as being harmful to Li[Ni0.8Co0.15Mn0.05]O2 (NCM) performance, leading to significant performance losses and also hampering the electrode fabrication. Therefore, manufacturers try their best to lower sulfate contents in pre‐NCM. However, how the sulfate affects the cathode materials is not systematically studied. To address these issues, NCM was synthesized with different amounts of intentionally added sulfate (NH4)2SO4 in pre‐NCM. It was demonstrated that anionic SO42− doped in NCM could influence the grain size in sintering process and stabilize the layer structure during the charge–discharge process at a certain doping amount. The first‐principles calculations suggested that the SO42− doped in the transition metal layer could effectively facilitate Li+ diffusion in the lattice. SO42− doping could reduce the energy barrier for Li+ migration and then suppress drastic contraction of the c axis during cycling. The phase transition of H2 to H3 caused by c axis contraction was suppressed and the cycling performance was enhanced. The capacity retention could reach 80.9 (0.2 C) and 80.4 % (1 C) after 380 and 240 cycles in coin cells, respectively. These findings illustrate that a certain amount of sulfate could be beneficial to NCM cathodes. [ABSTRACT FROM AUTHOR]

Rechargeable Na‐air batteries are the subject of great interest because of their high theoretical specific energy density, lower cost, and lower charge potential compared with Li‐air batteries. However, high purity O2 as a working environment is required to achieve high‐performance Na‐air batteries, which obstructs their application as a high‐energy‐density battery. Although aqueous Na‐air batteries can operate in ambient air, long cycle and high safety remain challenges for aqueous Na‐air batteries because the aqueous electrolyte is volatile. Here, a quasi‐solid‐state Na‐air battery is reported by utilizing a gel cathode, which is composed of single‐walled carbon nanotubes and room‐temperature ionic liquids, achieving high safety and long cycling life of 125 cycles (528 h) at a current density of 0.1 mA cm−2, which is surprisingly better than that of quasi‐solid‐state NaO2 batteries. In situ XRD characterizations reveal that water in ambient air is gradually deposited on the surface of the gel cathode to form a water layer, which facilitates the generation of soluble discharge product of NaOH thermodynamically with high conductivity. This work shall be critical to develop and promote the practical application of Na‐air batteries, opening a new way to the design of solid‐state metal‐air batteries. [ABSTRACT FROM AUTHOR]

In this work, an amorphous ZnO was coated on LiNi0.6Co0.2Mn0.2O2 (NCM) using a sol‐gel strategy method. The NCM coated with 1 wt.% ZnO and a thickness of about 3 nm exhibits an improved cycling performance, accompanied by a lower capacity fading (from 194.8 to 133.8 mAh g−1, i.e., 68%) than that of the pristine one (i.e., only 34%) after 300 cycles at 0.2 C. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) indicate that the ZnO coating can improve extraction/insertion of Li+ and inhibit the increase in impedance of the NCM cathode material. This approach may benefit the performance improvement of the Ni‐rich cathode materials in Lithium‐ion batteries (LIBs). [ABSTRACT FROM AUTHOR]

Abstract: Constructing high voltage (>4.5 V) cathode materials for sodium‐ion batteries has emerged in recent years to replace lithium batteries for large scale energy storage applications. Herein, an electrochemically stable Na0.66(Ni0.13Mn0.54Co0.13)O2 (Na‐NMC) buckyballs with an uniform size of 5 µm and a high tap density of 2.34 g cm−3, which exhibit excellent cyclability even at the high current with a cut‐off voltage of 4.7 V, is demonstrated. The Na‐NMC buckyballs are prepared from (Ni0.13Mn0.54Co0.13)CO3 (NMC) precursor synthesized using a facile hydrothermal method. The Na‐NMC delivers a reversible capacity of around 120 mAh g−1 between 4.7 and 2 V at 1 C rate along with an excellent cyclic stability (90%) until 150 cycles, which is one of the best outcomes among the reported P2‐type cathodes tested at the high operating voltage range. Furthermore, Na‐NMC‐180 buckyballs with a high tap density is offering an enhanced volumetric energy density, a superior rate performance and an outstanding cyclic stability. The X‐ray adsorption fine structure analysis is used to study the local electronic structure changes around the Co, Mn, and Ni after cycling process at 1 C rate. The findings open opportunities for tailoring high‐performance and high‐energy cathode materials for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: The room temperature (RT) sodium–sulfur batteries (Na–S) hold great promise for practical applications including energy storage and conversion due to high energy density, long lifespan, and low cost, as well based on the abundant reserves of both sodium metal and sulfur. Herein, freestanding (C/S/BaTiO3)@TiO2 (CSB@TiO2) electrode with only ≈3 wt% of BaTiO3 additive and ≈4 nm thickness of amorphous TiO2 atomic layer deposition protective layer is rational designed, and first used for RT Na–S batteries. Results show that such cathode material exhibits high rate capability and excellent durability compared with pure C/S and C/S/BaTiO3 electrodes. Notably, this CSB@TiO2 electrode performs a discharge capacity of 524.8 and 382 mA h g−1 after 1400 cycles at 1 A g−1 and 3000 cycles at 2 A g−1, respectively. Such superior electrochemical performance is mainly attributed from the “BaTiO3‐C‐TiO2” synergetic structure within the matrix, which enables effectively inhibiting the shuttle effect, restraining the volumetric variation and stabilizing the ionic transport interface. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries are widely considered as promising energy storage systems for large-scale applications, but their relatively low energy density hinders further practical applications. Developing high-voltage cathode materials is an effective approach to increase the overall energy density of sodium-ion batteries. When cut-off voltage is elevated over 4.3 V, however, the cathode becomes extremely unstable due to structural transformations as well as metal dissolution into the electrolytes. In this work, the cyclic stability of P2-Na0.66(Mn0.54Co0.13Ni0.13)O2 (MCN) electrode at a cut-off voltage of 4.5 V is successfully improved by using ultrathin metal oxide surface coatings (Al2O3, ZrO2, and TiO2) deposited by an atomic layer deposition technique. The MCN electrode coated with the Al2O3 layer exhibits higher capacity retention among the MCN electrodes. Moreover, the rate performance of the MCN electrode is greatly improved by the metal oxide coatings in the order of TiO2 < Al2O3 < ZrO2, due to increased fracture toughness and electrical conductivity of the metal oxide coating layers. A ZrO2-coated MCN electrode shows a discharge capacity of 83 mAh g−1 at 2.4 A g−1, in comparison to 61 mAh g−1 for a pristine MCN electrode. Cyclic voltammetry and electrochemical impedance analysis disclose the reduced charge transfer resistance from 1421 to 760.2 Ω after cycles, suggesting that the metal oxide coating layer can effectively minimize the undesirable phase transition, buffer inherent stress and strain between the binder, cathode, and current collector, and avoid volumetric changes, thus increasing the cyclic stability of the MCN electrode. [ABSTRACT FROM AUTHOR]

Prussian blue and its analogs (PB/PBAs) are competitive candidates for cathode materials of rechargeable metal-ion batteries (monovalent metal such as Na and K and multivalent metal, e.g. Mg, Ca, Zn, and Al) due to their stable frame structures, tunable redox sites, and facile synthesis methods. This paper comprehensively reviews the research progress of PB/PBAs-based cathode materials of metal-ion batteries in terms of their synthesis, structural/composition characteristics, electrochemical performance, functional mechanisms, applications and recycling in electrical energy storage. For facilitating the research and development, some technical challenges are analyzed and future research directions are also proposed for overcoming the challenges toward their practical applications. [Display omitted] • PB/PBAs are potential cathode materials for low-cost metal-ion batteries. • The modification principles of PB/PBAs for inherent challenges are summarized. • The future orientation development of PB/PBAs in batteries is provided. [ABSTRACT FROM AUTHOR]

Nitrogen-doped graphene nanosheets (N-GNSs) displayed a discharge capacity two times greater than their pristine counterpart, as well as superior electrocatalytic activity as a cathode material for sodium–air batteries. The enhanced performance of N-GNSs is attributed to the active sites introduced by nitrogen doping. [ABSTRACT FROM AUTHOR]

Exploring high performance and environment-friendly electrode materials is highly desirable for the sustainable Li-ion batteries (LIBs) system. In this study, a facile approach of the modified Hummers’ method combining with special thermal reduction was proposed to synthesize nanostructured reduced graphene oxide (RGO) with abundant oxygen-containing functional groups. The resultant RGO showed high specific capacity and excellent cyclability as cathode materials for LIBs. The specific capacity of about 220 mAh g −1 at a current density of 50 mA g −1 was achieved after 100 cycles. More importantly, it was demonstrated that the capacity increased with the increase of the amount of oxygen functional groups, highlighting the significant effects of oxygen-containing functional groups of RGO on high lithium storage performance. [ABSTRACT FROM AUTHOR]

Abstract: LiCoO2 in the commercial lithium ion batteries has been suffering from its poor cycling performance at high cutoff voltages. In this study, we employ an atomic layer deposition (ALD) technique to surface-modify a LiCoO2 material with various thickness-controlled metal oxide (TiO2, ZrO2 and Al2O3) coatings to improve its battery performance. The effects of the metal oxide coatings on the electrochemical performance of LiCoO2 electrode are studied in detail. It is demonstrated that a uniform and dense coating via the ALD route on LiCoO2 powder can lower the battery performance due to an obvious decrease in lithium diffusion and electron transport with the coating layers. In contrast, it is revealed that a direct coating on prefabricated LiCoO2 electrodes performs much better than a coating on LiCoO2 powders. It is further disclosed that the improved electrochemical performance of coated LiCoO2 electrode is highly dependent on the coating materials. Of the three coating materials, the Al2O3 coating results in the best cycling stability while the ZrO2 coating contributes to the best rate capability. It is thus suggested that the coating materials are functionally specific, and for the best improvement of a cathode, a particular coating material should be sought. [Copyright &y& Elsevier]

Abstract: Carbon materials have been widely used as cathodes in lithium oxygen batteries but the detailed influence of the structure of these materials on their performance is not very clear yet. In this study, the same starting pristine commercial carbon black (N330) was treated under different atmospheres and the resultant carbons were employed as cathode materials for lithium oxygen batteries. It was demonstrated that the porosity and surface topology of these carbons tremendously changed as their treating time increased. The parameters that influenced the battery performance were identified. It was found that the main factor determining the battery performance is the specific surface area of the carbon mesopores, while nitrogen- or oxygen-bearing functionalities, introduced in these carbons during their heat-treatment or by contact with air after their pyrolysis, had little or no influence on the battery performance. [Copyright &y& Elsevier]

Abstract: Nonaqueous lithium-oxygen battery with nitrogen-doped graphene nanosheets (N-GNSs) as cathode materials delivered a discharge capacity of 11660mAhg−1, which is about 40% higher than that with the pristine graphene nanosheets (GNSs). The electrocatalytic activity of N-GNSs for oxygen reduction in the nonaqueous electrolyte is 2.5 times as that of GNSs. The excellent electrochemical performance of N-GNSs is attributed to the defects and functional groups as active sites introduced by nitrogen doping. [Copyright &y& Elsevier]

Abstract: Nitrogen-doped carbon nanotubes (N-CNTs) were synthesized by a floating catalyst chemical vapor deposition (FCCVD) method. Various techniques including X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy revealed the morphology and structure of CNTs and N-CNTs as well confirmed the existence of incorporated nitrogen (10.2at.%) in N-CNTs. N-CNTs were investigated as cathode material for lithium–air batteries and exhibited a specific discharge capacity of 866mAhg−1, which was about 1.5 times as that of CNTs. Our results indicated that the N-CNTs electrode showed high electrocatalytic activities for the cathode reaction thus improving the lithium–air battery performance. [Copyright &y& Elsevier]

Microporous carbon (MPC) was synthesized from polyvinylidene fluoride (PVDF) using an activation-free approach and used as a selenium host for high-performance lithium-selenium (Li-Se) batteries. The microporous carbon/selenium (MPC/Se) composites were applied a cathode in Li-Se batteries with a carbonate-based electrolyte. The influences of PVDF carbonization temperature (600 °C, 700 °C and 800 °C) and Se content (50 wt%, 60 wt%, and 70 wt%) in the cathode were investigated in order to establish correlation between MPC structure and MPC/Se electrochemical performance. The results revealed that the MPC/Se composite cathode, with MPC synthesized at 800 °C and with a Se content of 50 wt%, exhibited a superior reversible capacity of 508.8 mAh g−1 at 0.1C after 100 cycles. Moreover, the MPC/Se maintained a capacity retention of 354.0 mAh g−1 at 0.5C for 200 cycles. The reason for the excellent performance could be attributed to the dominant microporous feature of MPC, which could effectively confine Se and reduce side reactions with electrolytes. Furthermore, increasing Se content from 50 wt% to 70 wt% leaded to decrease in the specific capacity and rate capability of MPC/Se cathode, due to significantly reduced Li-ion diffusion coefficient. This work suggested the effectiveness of MPC derived from commercial PVDF through an activation-free and scalable approach as Se hosts for high-performance Li-Se batteries. Image 1 • One-step activation-free synthesis of microporous carbon (MPC) from PVDF. • MPC/Se showed high excellent performance as cathode in Li-Se batteries. • Properties of MPC/Se depend on pore size and volume, and Se content in MPC/Se. • Micropores and micropore volume are the key merits for porous carbon as the Se host. [ABSTRACT FROM AUTHOR]