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The development of high‐performance cathode materials for next‐generation lithium‐ion batteries (LIBs) is urgently needed. Among the potential cathode candidates, ternary layer oxide LiNi1/3Co1/3Mn1/3O2 (LNCM) has attracted considerable attention due to its high voltage discharge, large theoretical specific capacity, stable chemical structure and low cost. However, Li+/Ni2+ cation mixing and low conductivity have resulted in poor long‐term cyclability, voltage drop and capacity degradation during high‐rate charging. To address these issues, a sol‐gel technique together with an annealing treatment was used to prepare LNCM with well‐defined structure and good morphology. The material obtained by heating the LNCM precursor at 850 °C for 12 h (LNCM‐850/12) exhibited an initial discharge specific capacity of 217.9 mAh g−1 at 0.2 C and maintained a high reversible capacity of 116.1 mAh g−1 after 200 cycles. The LNCM‐850/12 electrode also demonstrated superior rate capacity and exceptional cycling stability due to its well‐defined structure, low Li+/Ni2+ cation mixing and good morphology. These characteristics improve the electrical/ionic conductivity, reduce the charge transfer resistance and shorten the Li+ diffusion distance, ultimately accelerating the Li+ insertion and extraction. Overall, the careful control of calcination time in LNCM synthesis provides valuable insights for the development of advanced cathodes for LIBs. [ABSTRACT FROM AUTHOR]

• NVO are prepared using Pluronic-F127 as structure-directing agent. • NVO show unique nanorod structures. • NVO calcined at 400 °C shows high capacity and high rate capability. • Kinetics analysis verifies the pseudocapacitive behavior of R-400. • Outstanding performance is attributed to low resistance and fast Na+ ions intercalation/deintercalation kinetics. In this study, NaV 3 O 8 nanorods are successfully prepared using nonionic surface-active agents Pluronic-F127 as structure-directing agent. The as-prepared NaV 3 O 8 nanorods calcinated at different temperatures are characterized by various techniques, including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy. The NaV 3 O 8 calcinated at 400 °C for 20 h shows appropriate sizes and uniform morphologies of the nanorods, 4–7 μm in length and 0.2–0.5 μm in diameter. The NaV 3 O 8 nanorods as cathode materials for Na-ion batteries deliver high discharge capacity reaching up 110.4 mAh g−1 at current density of 120 mA g−1, as well as long lifespan by maintaining capacity of 162.1 mAh g−1 after 500 charge-discharge cycles. Also, a high reversible capacity of 83.9 mAh g−1 can be retained after 500 cycles at high rate of 2 A g−1. The obtained outstanding electrochemical performances are associated with the unique micro-nano structures, which does not only facilitate transport of Na+ ion, but also resist erosion from electrolytes. Overall, the results suggest the promise of NaV 3 O 8 nanorods as cathode materials for high capacity, high power and long lifespan Na-ion batteries. This work may open an innovative route to discover diverse electrode materials with nanostructure for energy storage system. [ABSTRACT FROM AUTHOR]

Abstract A series of LiNi 1/3 Co 1/3 Mn 1/3 O 2 /polytriphenylamine composites were successfully synthesized by ultrasound dispersion method. LiNi 1/3 Co 1/3 Mn 1/3 O 2 /polytriphenylamine (5.0 wt%) composite with small and homogeneous particle size exhibited excellent electrochemical performance, which delivered an initial discharge capacity of 223.7 mAh g−1 with a capacity retention of 84.39% after 100 cycles in the voltage range of 2.5–4.5 V and at a current density of 0.2C. Moreover, an excellent specific discharge capacity of 127.3 mAh g−1 at a current density 5C indicates a superior rate performance of the LiNi 1/3 Co 1/3 Mn 1/3 O 2 /polytriphenylamine (5.0 wt%) composite. The good electrochemical performances of the composite can be attributed to the introduction of polytriphenylamine, which increased electrical conductivity, decreased charge transfer resistance and increased Li+ ion diffusion ability. These noteworthy results demonstrated that LiNi 1/3 Co 1/3 Mn 1/3 O 2 /polytriphenylamine composites might be potential cathode materials for lithium ion batteries. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

• 1. For the first time, the Li 7 [V 15 O 36 (CO 3)] and γ -LiV 2 O 5 as host materials to store Zn2+. • 2. A larger voltage window (0.2–1.9 V) than most other aqueous zinc ion batteries. • 3. The energy density and power density of the Li 7 [V 15 O 36 (CO 3)] and the γ -LiV 2 O 5 is high. • 4. The Zn2+ storage mechanisms of the Li 7 [V 15 O 36 (CO 3)] and the γ -LiV 2 O 5 are proved. Recently, many reports have been published about polyoxovanadates (POVs) with multiple electrons redox activity for energy storage. However, they are easily transformed into solid-state oxides after calcination. We noted that although dehydrated Li 7 [V 15 O 36 (CO 3)] (Li 7 V 15) exhibited a high capacity for lithium-ion batteries (LIBs), it was reported that the electrochemical behavior of the dehydrated sample same as γ -LiV 2 O 5 (γ -LVO) which prepared by annealing the cluster and undehydrated Li 7 V 15 was not redox-active. Interestingly, we were surprised to find that undehydrated Li 7 V 15 and its derivative γ -LVO showed better electrochemical performance than LIBs when first proposed as the cathode to store Zn2+. Both Li 7 V 15 and γ -LVO electrodes provided excellent rate performance and satisfied cyclability (135.0 and 214.1 mAh g−1 at 3 A g−1 after 1000 cycles, respectively). The fast kinetics of Li 7 V 15 and γ -LVO were verified by pseudocapacitive analysis, GITT and EIS tests. Moreover, the Zn2+ storage mechanism and redox behavior of Li 7 V 15 and γ -LVO were examined by ex-situ measurements. First-principles calculations revealed that the Zn2+ was chemisorbed on the clusters and physisorbed between the clusters. This work enriches the POVs cathode chemistry in aqueous energy storage. [ABSTRACT FROM AUTHOR]

The development of lithium-ion batteries is hindered by the lack of appropriate low-cost cathode materials with high performance. Here, the preparation of Cu-coated Li 3 V 2 (PO 4) 3 /C (x % Cu-LVPC) composites is reported via a chemical precipitation and self-reduction method. With an optimized Cu coating content of 2.0 wt%, the 2.0% Cu-LVPC composite displays the best electrochemical properties. The initial discharge capacity of 2.0% Cu-LVPC is 175 mA h g−1 at 0.15 C (30 mA g−1) in the voltage range from 3.0 to 4.8 V and the capacity retention is 86.3% after 50 cycles, whereas pristine LVPC has an initial capacity of 163 mA h g−1 and retains 82.2% of the capacity after 50 cycles. Moreover, the rate capacity of 2.0% Cu-LVPC is also increased under different current densities and 2.0% Cu-LVPC exhibits excellent long-term cycling performance of 89 mA h g−1 after 1000 cycles at 10 C. The enhanced electrochemical properties are attributed to the uniform coating of the metal conductor Cu on the LVPC surface, which is conducive to electron transfer and extraction/insertion of Li+ ions. • Cu-coated Li 3 V 2 (PO 4) 3 /C (LVPC) was prepared via a chemical precipitation and self-reduction method. • The 2.0% Cu-coated LVPC composite exhibits significantly improved electrochemical performance. • Cu coating can effectively increase the conductivity of LVPC. • Cu coating on the surface of LVPC can reduce the polarization. [ABSTRACT FROM AUTHOR]

In this work, it is proved that carbon coated nanospheres structure can effectively enhance the reaction stability, the transmission speed of electrons and ionic conductivity of Sb-based materials. Due to Ni-Co-Sb/C material has the high specific surface area, low charge transfer resistance and special alloying mechanism displayed admirable electrochemical properties as anode materials for LIBs. The synthetic strategy and lithium storage mechanism may provide a new insight into the preparation of high-performance Sb-based electrode materials for LIBs. The strategy of "template sacrifice method" was proposed to synthesize well-defined NiSb/CoSb nanoparticles embedded in carbon nanosphere (Ni-Co-Sb/C, ~560 nm) by calcination treatment of the Ni-Co-MOF (metal-organic framework) precursor. Due to the structural controllability of MOF precursor and Ni/Co bimetallic synergy, the fabricated Ni-Co-Sb/C demonstrates a high surface area (88 m2 g−1) and superior ion conductivity, thus an excellent electrochemical performance as has been achieved as lithium ion battery (LIB) anode. A reversible discharge specific capacity as high as 495.1 mAh g−1 has been stably delivered after 1000 cycles at a high current density of 1.0 A g−1. In addition, the charge transfer impedance of Ni-Co-Sb/C electrode is as low as 67.6 Ω in the 30th cycle at 0.1 A g−1 and the pseudocapacitive contribution is as high as 73.8% at 0.5 mV s−1. The alloying mechanism of Ni-Co-Sb/C has been verified by in-situ X-ray diffraction (XRD), which enables a high lithium storage capacity. Moreover, the full-cell assembled with LiCoO 2 as cathode exhibits a steady discharge specific capacity of 354.0 mAh g−1 at 0.1 A g−1 even after 100 cycles. Our work provides an effective method for the application and high-capacity Sb-based material in energy storage fields, and this material is expected as a promising candidate for a novel anode material in LIBs. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) have garnered significant academic and industrial focus because of their excellent merits, like high voltage, high energy density, excellent cyclic performance, no memory effect and environment-friendly nature. So far, the electrochemical properties of LIBs are restricted by the capacity of cathode materials and various novel compositions and designed architectures have been proposed to enhance the energy density and cyclic performance of LIBs cathodes. Recently, lithium nickel cobalt manganese oxides have attracted extensive research interest owing to the united advantages of LiCoO 2 , LiNiO 2 and LiMnO 2. Herein, we have reviewed the recent developments of LiNi 1/3 Co 1/3 Mn 1/3 O 2 from the viewpoint of synthesis processes and structural designs. The electrochemical properties of LiNi 1/3 Co 1/3 Mn 1/3 O 2 depend on particle size, morphology, ion doping and surface coating of the as-prepared cathode powder. The present article summarizes the recent developments and provides an insight into the future roadmap for the realization of high energy density LIBs. • Main synthesis methods of NCM cathodes are summarized and analyzed. • Partial ionic substitution enhances the structural stability and electronic conductivity. • Surface coating can prevent the side reactions, improved the electronic and ion migration rate. • Composite structure can increase the structure constancy and the electronic conductivity. [ABSTRACT FROM AUTHOR]

• Substitution ions can affect the lattice constants, grain size and morphology. • Doping sites include Li, V, O sites, cation and anion co-doping, interlayer doping. • Ions-doping improves the diffusion coefficient and the electronic conductivity. • Ions-doping is an important trend for the long-term development of Li 1+ x V 3 O 8. Compared with other materials, monoclinic Li 1+ x V 3 O 8 as the promising cathode includes many strong points, such as high theoretical capacity, abundant raw materials, safety characteristic and low environmental impact. However, the primary problems facing the development of Li 1+ x V 3 O 8 for energy storage devices are poor cycling performance, low rate capability and short service life. Recently, many researches have taken various measures to overcome these shortcomings. In this mini-review, we summarized the recent developments of Li 1+ x V 3 O 8 and focus on the improving of Li 1+ x V 3 O 8 by ions-doping, which is deemed to a significant manner to improve the electrochemical performances of Li 1+ x V 3 O 8. [ABSTRACT FROM AUTHOR]

In this study, Ag 2 V 4 O 11 was employed as an additive to boost the electrochemical performance of Li 4 Ti 5 O 12. A series of Li 4 Ti 5 O 12 /Ag 2 V 4 O 11 composites with different Ag 2 V 4 O 11 mass ratios of 3 wt.%, 5 wt.% and 8 wt.% were prepared using liquid-phase dispersion method to yield compounds abbreviated as Li 4 Ti 5 O 12 /Ag 2 V 4 O 11 (3 wt.%), Li 4 Ti 5 O 12 /Ag 2 V 4 O 11 (5 wt.%) and Li 4 Ti 5 O 12 /Ag 2 V 4 O 11 (8 wt.%), respectively. Among them, Li 4 Ti 5 O 12 /Ag 2 V 4 O 11 (5 wt.%) composite displayed a considerable initial discharge specific capacity of 252.4 mAh g −1 at 30 mA g −1 which still maintained at 152.0 mAh g −1 over 500 cycles. At 1200 mA g −1, a capacity of 69.0 mAh g −1 was retained over 5,000 cycles. The electrode kinetic studies revealed that the introduction of Ag 2 V 4 O 11 phase boosted the transport rate of lithium ion and the electronic conductivity of Li 4 Ti 5 O 12. In-situ XRD tests related that Ag 2 V 4 O 11 was decomposed to in situ produce metallic Ag on Li 4 Ti 5 O 12 after cycle. In a word, Li 4 Ti 5 O 12 /Ag 2 V 4 O 11 (5 wt.%) composite was a promising as the electrode material in lithium-ion batteries. The data also provided a fire-new method to enhance the electrochemical property of Li 4 Ti 5 O 12. [ABSTRACT FROM AUTHOR]