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Prussian blue is a potential cathode candidate for sodium-ion batteries because of inexpensiveness and high theoretical capacity, while the poor rate performance hinders its widely practical application. In this work, the Prussian blue is directly grown on poly3,4-ethylenedioxythiophene decorated multi-wall carbon nanotubes (denoted as PB/CNT@PEDOT), where the CNT@PEDOT can provide improved electrical conductivity and lower the size of PB. Thus, the PB/CNT@PEDOT shows a discharge capacity of 85 mAh g−1 after 100 cycles at 0.2C. Compare to PB and PB/CNT, the PB/CNT@PEDOT delivers enhanced rate capability with 90 mAh g−1 retention at 5C. [ABSTRACT FROM AUTHOR]

The shuttle effect of lithium polysulfides in lithium‐sulfur batteries (LSBs) has a detrimental impact on their electrochemical performance. To effectively mitigate the shuttle effect, in this study, the coral‐like CuS is introduced to modify the carbon nanotube (CNTs), which is coated on commercial separator and served as the S cathode interlayer (PE@CuS/CNTs). The CuS/CNTs interlayer possesses efficient physical impediment and chemisorption to polysulfide anions. When achieving maximum adsorption to polysulfide anions, a "polysulfide‐phobic" surface would be formed as a shield to restrain the polysulfide anions in the cathode region. Simultaneously, the CuS/CNTs interlayer can improve the lithium ion diffusion and guarantee desirable electrochemical reaction kinetics. Consequently, the LSBs with PE@CuS/CNTs show an initial discharge capacity of 1242.4 mAh g−1 at 0.5 C (1 C = 1675 mA g−1) and retain a long‐term cycling stability (568.5 mAh g−1 after 1000 cycles, 2 C), corresponding to an ultra‐low capacity fading rate of only 0.05% per cycle. Also, the LSBs with PE@CuS/CNTs exhibit high resistance to self‐discharge and favorable performance under high S loading (4.5 mg cm−2) and lean electrolyte (9.4 mLElectrolyte g S−1). [ABSTRACT FROM AUTHOR]

The unpredictable growth of lithium (Li) dendrite is one of the crux issues in the commercial application of the Li‐metal batteries (LMBs). Herein, a flexible PVDF‐HFP/LiClO4/NaTi2(PO4)3 (NTP) layer modified polypropylene (PP) separators are designed to achieve homogeneous nucleation and growth of Li. The introduction of NTP particles not only reduces the crystallinity of the polymer but also generates a rapid Li+ migration pathway at the interface, which is conducive to regulating the Li+ flux and guiding the uniform Li deposition by improving ionic conductivity. In addition, because of the high electrolyte wettability and the enhanced mechanical strength of the functionalized separator, the mass transport capability is promoted and the penetration of Li dendrite can be avoided. Consequently, the modified separators with 20 wt% NTP (PP@PHNTP‐20) endow Cu||Li batteries with an excellent average Coulombic efficiency of ≈99%. Furthermore, the long‐term reversible Li plating/stripping can be achieved in the Li symmetric battery, and the LiFePO4 (LFP) ||Li batteries with PP@PHNTP‐20 present high capacity retention and improved C‐rate performance in a carbonate‐based electrolyte without additives. [ABSTRACT FROM AUTHOR]

The uncontrollable lithium (Li) dendrite growth during repeated cycles is a safety risk and is an undesirable electrochemical property of Li metal batteries (LMBs) that hinders the commercialization of LMBs. To realize a dendrite-free Li anode, a hierarchical lithiophilic current collector was fabricated with Sb modified Cu nanowires on Cu foam (1D@3D-Cu/Sb). The 3D porous Cu foam scaffolds have ample space which can buffer the volume changes and provide a reduced local current density. Moreover, the Sb modified 1D Cu nanowires with a secondary structure of an homogenized Li+ flux provide numerous lithiophilic sites for uniform Li+ deposition, further suppressing the Li dendrite formation. Consequently, the 1D@3D-Cu/Sb as a Li host operates for over 900 h with a low overpotential (∼11 mV) without intense voltage fluctuation for symmetrical cells. Furthermore, the full cells pairing Li-deposited 1D@3D-Cu/Sb with a LiFePO4 (LFP) cathode achieves promising cycling stability for 200 cycles at 0.5C. [ABSTRACT FROM AUTHOR]

Ni‐rich LiNi0.8Co0.1Mn0.1O2 (NCM811) has been considered as a promising cathode material for high energy density lithium‐ion batteries. However, it experiences undesirable interfacial side‐reactions with the electrolyte, which lead to a rapid capacity decay. In this work, a homogeneous precipitation method is proposed for forming a uniform silicon dioxide (SiO2) coating on the NCM811 surface. The strong Si−O network provided a stable protective layer between the NCM811 active material and electrolyte to improve the electrochemical stability. As a result, the NCM811@SiO2 cathode showed superior cycling stability (84.9 % after 100 cycles at 0.2 C) and rate capability (142.7 mA h g−1 at 5 C) compared to the pristine NCM811 cathode (56.6 % after 100 cycles, 127.9 mA h g−1 at 5 C). Moreover, the SiO2 coating effectively suppressed voltage decay and pulverization of the NCM811 particles during long term cycling. This uniform coating technique offers a viable approach for stabilizing Ni‐rich cathode materials for high‐energy density lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

Rational regulation of host–guest interactive chemistry is of great significance but has not yet effectively been applied in lithium–sulfur (Li–S) batteries. Herein, a unique titanium vanadium nitride (TVN) solid solution fabric is developed as an ideal platform for fine structure modulation towards efficient and durable sulfur electrochemistry. The dissolution of V into the TiN lattice framework is shown to subtly tailor the coordinative and electronic structures of Ti and V, tuning their respective chemical affinity to sulfur species. Consequently, the optimized Ti–V interplay renders the highest overall polysulfide adsorpabiltiy, and contributes to strong sulfur immobilization and fast reaction kinetics. The resultant Li–S cells realize an outstanding cyclability with high capacity retention of 97.7% after 400 cycles. Moreover, reversible areal capacity over 6.11 mAh cm−2 can be sustained under a high sulfur loading of 6.0 mg cm−2 and a limited electrolyte concentration of 6.5 mL g−1. This work provides a novel strategic perspective for the rational regulation of fine structure towards superior Li–S batteries and beyond. [ABSTRACT FROM AUTHOR]

The practical application of Li–S batteries demands low cell balance (Licapacity/Scapacity), which involves uniform Li growth, restrained shuttle effect, and fast redox reaction kinetics of S species simultaneously. Herein, with the aid of W2C nanocrystals, a freestanding 3D current collector is applied as both Li and S hosts owing to its lithiophilic and sulfilic property. On the one hand, the highly conductive W2C can reduce Li nucleation overpotentials, thus guiding uniform Li nucleation and deposition to suppress Li dendrite growth. On the other hand, the polar W2C with catalytic effect can enhance the chemisorption affinity to lithium polysulfides (LiPSs) and guarantee fast redox kinetics to restrain S species in cathode region and promote the utilization of S. Surprisingly, a full Li–S battery with ultralow cell balance of 1.5:1 and high sulfur loading of 6.06 mg cm−2 shows obvious redox plateaus of S and maintains high reversible specific capacity of 1020 mAh g−1 (6.2 mAh cm−2) after 200 cycles. This work may shed new sights on the facile design of full Li–S battery with low excessive Li supply. [ABSTRACT FROM AUTHOR]

Vanadium carbide embedded in a nitrogen-doped carbon matrix (VC@NCM) is synthesized as a 3D freestanding sulfur host. Owing to the high electrical conductivity (1.6 × 104 S cm−1) of VC and strong chemisorption and catalytic effect on sulfur species, Li–S batteries with VC@NCM deliver enhanced redox kinetics with ultralow capacity decay of 0.01% per cycle after 1000 cycles at 1C. This work identifies the effect of strong chemisorption and high electrical conductivity on high S utilization and cycle stability in Li–S batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) have shown great potential as a rival for next generation batteries, for its relatively high theoretical capacity and eco‐friendly properties. Nevertheless, blocked by the shuttle effect of lithium polysulfides (LPSs, Li2S4‐Li2S8) and insulation of sulfur, LSBs show rapid capacity loss and cannot achieve the practical application. Herein, a composite of carbon nanofibers coated by Co3S4 nanosheets (denoted as CNF@Co3S4) is successfully synthesized as freestanding sulfur host to optimize the interaction with sulfur species. The combination of the two materials can lead extraordinary cycling and rate performance by alleviating the shuttle of LPSs effectively. N‐doped carbon nanofibers serve as long‐range conductive networks and Co3S4 nanosheets can accelerate the conversion of LPSs through its electrocatalytic and chemical adsorption ability. Benefiting from the unique structure, the transporting rate of Li+ can be enhanced. Distribution of Li+ is uniform for enough exposed negative active sites. As a result, the cell with CNF@Co3S4 as sulfur host is able to stabilize at 710 mA h g−1 at 1 C after 200 cycles with average coulombic efficiency of 97.8% in a sulfur loading of 1.7 mg cm−2 and deliver 4.1 mA h cm−2 at 0.1 C even in 6.8 mg cm−2 for 100 cycles. [ABSTRACT FROM AUTHOR]

Germanium (Ge)‐based materials have been considered as potential anode materials for sodium‐ion batteries owing to their high theoretical specific capacity. However, the poor conductivity and Na+ diffusivity of Ge‐based materials result in retardant ion/electron transportation and insufficient sodium storage efficiency, leading to sluggish reaction kinetics. To intrinsically maximize the sodium storage capability of Ge, the nitrogen doped carbon‐coated Cu3Ge/Ge heterostructure material (Cu3Ge/Ge@N‐C) is developed for enhanced sodium storage. The pod‐like structure of Cu3Ge/Ge@N‐C exposes numerous active surface to shorten ion transportation pathway while the uniform encapsulation of carbon shell improves the electron transportation, leading to enhanced reaction kinetics. Theoretical calculation reveals that Cu3Ge/Ge heterostructure can offer decent electron conduction and lower the Na+ diffusion barrier, which further promotes Ge alloying reaction and improves its sodium storage capability close to its theoretical value. In addition, the uniform encapsulation of nitrogen‐doped carbon on Cu3Ge/Ge heterostructure material efficiently alleviates its volume expansion and prevents its decomposition, further ensuring its structural integrity upon cycling. Attributed to these unique superiorities, the as‐prepared Cu3Ge/Ge@N‐C electrode demonstrates admirable discharge capacity, outstanding rate capability and prolonged cycle lifespan (178 mAh g−1 at 4.0 A g−1 after 4000 cycles). [ABSTRACT FROM AUTHOR]

The sluggish oxygen reduction reaction kinetics hinders the development fuel cells, which needs effective electrocatalyst with low cost and high efficiency to realize 4 e− reduction processes. To alternate commercial Pt/C, herein, hollow carbon nanocubes were successfully prepared and evaluated as oxygen reduction electrocatalyst. Benefit from the effective abundant nitrogen species and unique hollow architecture, the hollow carbon nanocubes exhibit favorable oxygen reduction electrochemical performance with onset potential of 0.94 V, half‐wave potential of 0.82 V, and limited current density of 6.11 mA cm−2, which are comparable to those of Pt/C. Additionally, compared to Pt/C, the HC‐800 shows expressively stability and methanol tolerance. [ABSTRACT FROM AUTHOR]