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Transition metal oxides, especially bimetal oxides, are considered as one of the most promising anode materials for high‐performance lithium‐ion batteries (LIBs) due to their ultra‐high theoretical capacity. However, it is difficult to achieve fast charging at high rates due to the issues of poor electrical conductivity, large volume expansion, and poor reaction kinetics. The design of advanced nanostructured anode materials is very important to boost lithium storage performance. Herein, the multi‐hierarchical heterostructure material NiCo2O4/ZnCo2O4/Carbon Cloth (NCO/ZCO/CC) including carbon cloth substrate, ZnCo2O4 nanosheets, and NiCo2O4 nanowires is prepared as a binder‐free anode for LIBs. Benefiting from the special hierarchical nanostructure and the synergistic interaction of the component, the as‐prepared NCO/ZCO/CC anode material exhibits good electrical conductivity, structural stability, and electrochemical kinetics, which can provide a high reversible areal capacity of 2.55 mAh cm−2 at 2 mA cm−2 after 200 cycles. At a high current density of 5 mA cm−2, the NCO/ZCO/CC electrode only takes about 20 min to fully charge and it can still reach a capacity of 1.50 mAh cm−2 with a capacity retention of 86.2% after 400 cycles, revealing the potential for fast charging at high rates. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hierarchically interconnected porous conjugated polymer network was prepared. • The planar conjugated structure ensures a high electrical conductivity and efficient electron transfer in BT-CMP electrode. • Experiment and theoretical calculation reveal the cooperatively coupled potassium storage mechanism of S and N sites. • BT-CMP electrodes afford a high specific capacity and excellent cycle durability. Conjugated microporous polymers (CMPs) with enhanced electrical conductivity and insolubility against liquid electrolytes are receiving increasing attention as promising organic anode materials for rechargeable batteries. However, the poor electronic conductivity and restricted-access active sites limit the specific capacity and cycling stability of CMPs and the potassium-storage mechanism in hetero-incorporated CMPs not well understood. Herein, a highly conjugated polymer network with hierarchically interconnected porous structure was deliberately constructed by selecting 4,7-dibromo-2,1,3-benzothiadiazole (BT) and 1,3,5-triacetylene benzene as the acceptor and donor, respectively. The good planarity and high π-electron delocalization of BT units lead to an enhanced conductivity of BT-CMP. Ex-XPS analysis and DFT calculations reveal that the synergistic coupling of S and N enables a prompt complexation and release of K + ions and improves the coordination activity of the C N active sites. More importantly, the hierarchically interconnected porous networks make active sites facilely accessible and accommodate the volumetric expansion effectively, enabling highly stable storage of K-ions. Therefore, the as-prepared BT-CMP anode displays a high specific capacity (462 mAh/g−1 at 30 mA g−1 after 100 cycles) and ultra-long stability (226.2 mAh g−1 at 1000 mA g−1 after 2000 cycles without significant attenuation) in potassium-ion storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • Doping of Ga in octagon-square nitrogene increase its thermoelectric efficiency. • Salient electronic performance obtained from band convergence and p z orbital. • The κ L of doped system is about thirty times lower than nitrogen monolayer. • Lower κ L is due to increased scattering phase space and structural anharmonicity. Improving thermoelectric performance of self-powered operation of electronics has been a continuous effort to relieve energy crisis and environmental degradation. In the branches of thermoelectric research, multiscale phonon engineering and proper doping are effective strategies to reduce lattice thermal conductivity and enhance electrical conductivity of bulk materials, respectively, yet great challenge remains in the modulation of transport properties for low-dimensional structures. Here we propose to employ doping of Ga in the single-layer octagon-square nitrogene (OS-N) as an alternative way to increase its thermoelectric efficiency. Our work demonstrates that salient electronic performance can be obtained benefiting from the convergence of valence band as well as non-localized p z orbital state. At the same time, the relatively complexed configuration of doped system shows a much increased impeding of thermal transport, which is about thirty times lower than that of elemental two-dimensional nitrogene monolayer. This pronounced improvement is attributed to the softening of phonon branches, which increase the scattering phase space and structural anharmonicity. Our work illustrates the realization of tailoring electronic and phonon properties in the dimensionality reduced system and provides a road map for potential applying it in fields such as thermal management and thermoelectrics. [ABSTRACT FROM AUTHOR]

Here, we report a nano-sized red phosphorous/biomass-derived porous carbon (P@BDPC) which is employed as anode materials for lithium ion batteries (LIBs) via a facile vaporization−condensation−conversion strategy (VCC) with tobacco stem as the carbon precursor. The biomass-derived porous carbon not only acts as the host of red phosphorus to enhance the electrical conductivity, but also minimizes the volume expansion (≈400%) during cycling. The obtained P@BDPC composite with a high red phosphorus content (62.1 wt%) delivers a high specific capacity of 1689 mA h g−1 at 500 mA g−1 with an initial Coulombic efficiency (ICE) of 91.7% and superior rate capability of 599 mA h g−1 at 30 A g−1. Furthermore, a high reversible capacity of 918 mA h g−1 can be retained over 600 cycles at 5 A g−1, indicating a remarkable cycle stability. More importantly, the introduction of agriculture waste-tobacco stem contributes to building low-cost, high-performance anode materials. Synthetic route of the P@BDPC. Image 1 • Red P was successfully confined to nanoscale in N-doped porous carbon matrix. • The N-doped porous carbon ensures solid capture of red P and fast ion diffusion. • The red P/carbon composite exhibits superior specific capacity and rate capability. • A long cycle-life of 918 mA h g−1 at 5 A g−1 after 600 cycles was also achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • A closed-ended Sn 4 P 3 HS@MXene hybrid is fabricated by electrostatic self-assembly. • A thin and stable SEI is built and the electrode durability reinforced. • Extraordinarily high capacity of 302.1 mAh g−1 is achieved even at an ultrahigh rate of 10 A g−1. • The full-cell displays a capacity of 390.5 mAh g−1 at 1 A g−1 after 500 cycles. The development of sodium-ion batteries has been seriously discouraged by the major limitation in the rate capability and the cycle life of the anode materials. Sn 4 P 3 is recognized as a potential anode for sodium -ion batteries owing to its ultrahigh specific capacity and low cost, but the great volumetric change and low intrinsic electrical conductivity severely limit the cycling performance. Herein, we propose a closed-ended MXene and Sn 4 P 3 hybrid consisting of active Sn 4 P 3 porous hollow nanospheres (Sn 4 P 3 HS) armored by a conductive MXene shell. Notably, the outer MXene shell protects Sn 4 P 3 from direct exposure to the electrolyte and only allows the inward expansion of Sn 4 P 3 into the hollow space, resulting in the formation of a thin solid-electrolyte interphase layer of high stability. As predicted, the hybrids can deliver an extraordinarily high capacity of 302.1 mAh g−1 even at an ultrahigh rate of 10 A g−1 and cycle at 1 A g−1 for 1500 cycles with a capacity retention of 94.9%. Moreover, the Sn 4 P 3 HS@MXene//Na 3 V 2 (PO 4) 3 /C full cell exhibits an outstanding energy density of 287.8 Wh kg−1 and good cyclic ability (390.5 mAh g−1 at 1A g−1 after 500 cycles), exhibiting a great potential in practical application. [ABSTRACT FROM AUTHOR]

MXene has been recognized as a promising anode for sodium-ion batteries (SIBs) owing to its high electrical conductivity and long-term durability. But the low energy density and agglomeration-prone nature extensively preclude their application similar to that of other two-dimensional (2D) materials. This work transformed 2D MXene to a three-dimensional (3D) conductive network by incorporating Sn and Sn 4 P 3 nanoparticles between the MXene sheets. The homogenous distribution of ultrasmall Sn nanoparticles (∼4 nm) ensures a highly conductive network not only along the MXene planes but also perpendicular to them, while the covalent-bonded Sn 4 P 3 nanoparticles significantly reinforce the structural stability. Additionally, in/ex situ characterizations reveal a considerably high reversibility of the Na+ insertion/extraction process in the network. Benefiting from the rational design, the 3D conductive network yields an enhanced capacity, long-term cycling stability (127.2 mAh g−1 after 1000 cycles at 5 A g−1), and superior pseudocapacitive properties. • Tin and tin phosphide prevent MXene sheets from stacking. • Metallic Sn improves the conductivity perpendicular to the MXene planes. • The Sn-rich environment effectively activates tin phosphide electrochemically. • Enhanced cyclic stability is obtained over 1000 cycles at 2 and 5 A g−1. [ABSTRACT FROM AUTHOR]

• N-doped porous graphitized carbon spheres have been fabricated as sulfur host. • The in situ formed Fe nanoparticles play double roles as graphitization catalyst and pore template. • The electrical conductivity of the N-doped porous graphitized carbon spheres reaches 5.6 S cm−1. • The pomegranate-like S@N-doped graphitized carbon display good Li-ion storage performance. To obtain high-performance sulfur cathode for lithium-sulfur (Li-S) battery, porous graphitized carbon spheres with N doping have been fabricated via an in situ Fe catalysis as sulfur host. The in situ generated Fe nanoparticles play double roles as graphitization catalyst and pore template. The electrical conductivity of the graphitized sample (5.6 S cm−1) is about one order of magnitude higher than that of the amorphous carbon sample (0.63 S cm−1). Correspondingly, the pomegranate-like S@N-doped graphitized carbon cathode displays very good electrochemical performance. A capacity of 600 mAh g−1 is obtained after 150 charge/discharge cycles at a current density of 1 C with a sulfur content of 73 wt%. The pomegranate-like S@N-doped graphitized carbon is promising cathode candidate for high-performance Li-S battery. [ABSTRACT FROM AUTHOR]