Coaxial spinning fabricated high nitrogen-doped porous carbon walnut anchored on carbon fibers as anodic material with boosted lithium storage performance

C-Doped LiVO3 Honeycombs Derived from the Biomass Template Strategy for Superior Lithium Storage

LiVO3 as a prospective anode for lithium-ion batteries has drawn considerable focus based on its superior ion transfer capability and relatively elevated specific capacity. Nevertheless, the inherent low electrical conductivity and sluggish reaction kinetics hindered its commercial application. Herein, C-doped LiVO3 honeycombs (C-doped LiVO3 HCs) are designed via introducing low-cost and scalable biomass carbon as a template, and the influence of the structure on the lithium storage property is systematically studied. The prepared C-doped LiVO3 HC electrode delivers a high reversible capacity of 743.7 mA h g-1 at 0.5 A g-1 after 400 cycles and superior high-rate performance with an average discharge capacity of 420.8 mA h g-1 even at 5.0 A g-1. The remarkable comprehensive electrochemical performance is attributed to the high electrical conductivity caused by carbon doping and rapid ion transport triggered by the honeycomb structure. This work may offer a rational design on both the hierarchical structure and doping engineering of future battery electrodes.

Electrospun Nanofiber Electrodes for Lithium-Ion Batteries

Electrospun nanofiber materials have the advantages of good continuity, large specific surface areas, and high structural tunability, which provide many desirable characteristics for lithium-ion battery electrodes. Here, the principles and advantages of electrospinning technology are first elaborated, then the previous studies on high-performance nanofibrous electrode materials prepared by electrospinning technology are comprehensively summarized, and the correlation between 1D nanostructured materials and electrode performances is discussed. Finally, the remaining challenges of nanofibrous electrodes are proposed and some future study directions of this particular area are pointed out. This review provides new enlightenment for the design of nanofibrous electrodes toward high-performance lithium-ion batteries.

Interpenetrated N-rich MOF derived vesicular N-doped carbon for high performance lithium ion battery

High-performance lithium ion batteries (LIBs) juggling high reversible capacity, excellent rate capability and ultralong cycle stability are urgently needed for all electronic devices. Here we report employing a vesicle-like porous N-doped carbon material (abbr. N/C-900) as a highly active anode for LIBs to balance high capacity, high rate and long life. The N/C-900 material was fabricated by pyrolysis of a designed crystal MOF LCU-104, which exhibits a graceful two-fold interpenetrating structural feature of N-rich nanocages {Zn₆(dttz)₄} linked through an N-donor ligand bpp (H₃dttz = 4,5-di(1H-tetrazol-5-yl)-2H-1,2,3-triazole, bpp = 1,3-bis(4-pyridyl)propane). The features of LCU-104 combine high N content (35.1%), interpenetration, and explosive characteristics, which endow the derived N/C material with optimized N-doping for tuning its chemical and electronic structure, a suitably thicker wall to enhance its stability, and a vesicle-like structure to improve its porosity. As an anode material for LIBs, N/C-900 delivers a highly reversible capacity of ca. 734 mA h g^-1 at a large current density of 1 A g^-1 until the 2000th cycle, revealing its ultralong cycle stability and excellent rate capability. The unique structure and preferential interaction between abundant pyridinic N active sites and Li atoms are responsible for the improved excellent lithium storage capacity and durability performances of the anode according to analysis of the results of computational modeling.

N, O and S co-doped hierarchical porous carbon derived from a series of samara for lithium and sodium storage: Insights into surface capacitance and inner diffusion

Efficiently selecting biomass precursors to prepare porous carbon with rich pore structure and heteroatom doping, and clearly distinguishing the storage behavior of Li⁺ and Na⁺ in porous carbon are still the key issues for the development and utilization of biomass-based carbon materials. In this work, four kinds of samara with a hollow structure are used as carbon sources to prepare an N, O and S co-doped hierarchical porous carbon. As the anode for Li/Na-ion batteries, the reversible specific capacity of N, O and S co-doped hierarchical porous carbon (HPC-UP-6) is 1072.3 mAh·g^-1 (0.0744 A·g^-1) and 333.2 mAh·g^-1 (0.1 A·g^-1), respectively. The ultra-high specific capacity reveals the rationality of preferentially selecting plant fruits with hollow structures as precursors. In addition, further comparative studies show that the contribution rate of surface-induced capacitance in sodium-ion batteries is more than 10% higher than that in lithium-ion batteries, indicating that Na⁺ tends to be stored on the surface of porous carbon. This principle of selecting biomass precursors and the new understanding of the storage mechanism of Li⁺/Na⁺ in biomass-based porous carbon can guide the design and preparation of new carbon materials with high capacity and high-rate performance.

Self-assembly of carbon nanotubes on a hollow carbon polyhedron to enhance the potassium storage cycling stability of metal organic framework-derived metallic selenide anodes

Potassium-ion batteries (PIBs) is increasingly studied because of their suitable redox potential and high natural abundance. However, potential anode materials with long-term cycling stability are still in high demand because of the large radius of K⁺. Herein, an MOF-derived hierarchical carbon structure and the self-assembly of CNTs on hollow carbon polyhedrons are used as carbon matrices to disperse and stabilize metal selenides(Co-Se@CNNCP). When the hybrid is utilized in PIBs, it displays a specific capacity of 410 mA h g^-1 at 0.1 A g^-1 after 80 cycles and 253 mA h g^-1 at 0.5 A g^-1 after 200 cycles with a capacity retention of 100%, while the metal selenides dispersed on hollow carbon polyhedrons without CNTs (Zn-Co-Se@NCP) lose 86% of their capacity after 200 cycles. The superior cycling stability of the hybrid is mainly attributed to the large amounts of CNTs suppressing the agglomeration of the metal selenide nanoparticles on the surface, and the hollow carbon polyhedrons cause a high structural integrity during the repreated K⁺ insertion and extraction process. This work offers a feasible route to design a hierarchical carbon matrix for use as the anode materials of PIBs with long-term cycling stability.