Surfactant regulated Core-Double-Shell NF@NiO nanosheets matrix as integrated anodes for Lithium-Ion batteries

Natural Pitch-Derived Carbon Networks Induced Lattice Strain Engineering in Nickel-Based Heterostructures Enables Efficient Anodes for Sodium-Ion Batteries

The development of high-performance sodium-ion batteries (SIBs) relies on enhancing the electrochemical properties of the electrodes, particularly the transition metal compounds (TMCs) through effective carbon coatings. Herein, a straightforward approach using polymerized natural pitch-derived carbon (PNPC) via step-growth polymerization regulates the lattice strain in Ni3S2-NiO heterostructures (NSNO) on nickel foam (NF). This method replaces the complex multistep carbon coatings with a cost-effective liquid-phase application of PNPC, followed by pyrolysis to create PNPC@NSNO/NF. Comparative analysis shows that PNPC effectively modulates lattice strain, achieving 3.50% tensile strain compared to 5.60% for non-polymerized carbon. The optimized PNPC@NSNO/NF electrode exhibits exceptional high areal capacity of 2.72 mAh cm-2@1 mA cm-2, impressive rate capability, and 97.28% capacity retention after 200 cycles. The enhanced contact area and electrical conductivity provided by the PNPC improve charge transfer kinetics and overall performance. Theoretical analyses confirm that the PNPC@NSNO/NF electrode with 3.50% lattice strain lowers the Na⁺ diffusion barrier, enhances charge transfer, and improves charge distribution, boosting the electrode performance. This work establishes a straightforward method for synthesizing lattice-strained SIB anodes, highlighting its potential for advancing SIB technology.

Three-dimensional carbon coated and high mass-loaded NiO@Ni foam anode with high specific capacity for lithium ion batteries

Nickel oxide (NiO) is known for its remarkable theoretical specific capacity, making it a highly appealing option for electrode materials in electrochemical energy storage applications. Nevertheless, its practical use is limited by poor electrochemical performance and complicated electrode fabrication processes. To address these issues, we propose a new anode design comprising an intermediate NiO nanoarray layer and a carbon coating layer grown directly on a three-dimensional (3D) conductive nickel foam substrate, designated as C@NiO@Ni foam. This anode with a high NiO mass loading of 5-6 mg cm-2 is fabricated by a two-step process: thermal oxidation of the nickel foam, followed by carbon coating. The 3D architecture, with its large surface area, significantly enhances the contact between the electrode and electrolyte, thereby shortening the Li-ion diffusion pathway. Additionally, the carbon layer plays a crucial role in accommodating the volume changes of NiO during cycling, preventing the detachment of NiO from the Ni foam substrate, and enhancing the electronic conductivity of the C@NiO@Ni foam. The resulting porous C@NiO@Ni anode was thoroughly analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). When used as an anode material for lithium-ion batteries (LIBs), this anode showcased an impressive reversible capacity of around 678 mA h g-1 at 0.1C after 100 cycles. Furthermore, it demonstrated excellent electrochemical performance at a high current, sustaining a specific capacity of 387 mA h g-1 at 1C after 100 cycles.

Monolithic Microparticles Facilitated Flower-Like TiO2 Nanowires for High Areal Capacity Flexible Li-Ion Batteries

Flexible lithium-ion batteries (FLIBs) are intensively studied using free-standing transition metal oxides (TMOs)-based anode materials. However, achieving high areal capacity TMO-based anode materials is yet to be effectively elucidated owing to the poor adhesion of the active materials to the flexible substrate resulting in low active mass loading, and hence low areal capacity is realized. Herein, a novel monolithic rutile TiO2 microparticles on carbon cloth (ATO/CC) that facilitate the flower-like arrangement of TiO2 nanowires (denoted ATO/CC/OTO) is demonstrated as high areal capacity anode for FLIBs. The optimized ATO/CC/OTO anode exhibits high areal capacity (5.02 mAh cm-2@0.4 mA cm-2) excellent rate capability (1.17 mAh cm-2@5.0 mA cm-2) and remarkable cyclic stability (over 500 cycles). A series of morphological, kinetic, electrochemical, in situ Raman, and theoretical analyses reveal that the rational phase boundaries between the microparticles and nanowires contribute to promoting the Li storage activity. Furthermore, a 16.0 cm2 all-FLIB pouch cell assembled based on the ATO/CC/OTO anode and LiNiCoMnO2 cathode coated on ATO/CC (ATO/CC/LNCM) exhibits impressive flexibility under different folding conditions, creating opportunity for the development of high areal capacity anodes in future flexible energy storage devices.