Atomic layer deposition of Al2O3 on P2-Na0.5Mn0.5Co0.5O2 as interfacial layer for high power sodium-ion batteries

Indium Nitride Nanowires: Low Redox Potential Anodes for Lithium-Ion Batteries

Advanced lithium-ion batteries (LIBs) are crucial to portable devices and electric vehicles. However, it is still challenging to further develop the current anodic materials such as graphite due to the intrinsic limited capacity and sluggish Li-ion diffusion. Indium nitride (InN), which is a new type of anodic material with low redox potential (<0.7 V vs Li/Li+) and narrow bandgap (0.69 eV), may serve as a new high-energy density anode material for LIBs. Here, the growth of 1D single crystalline InN nanowires is reported on Au-decorated carbon fibers (InN/Au-CFs) via chemical vapor deposition, possessing a high aspect ratio of 400. The binder-free Au-CFs with high conductivity can provide abundant sites and enhance binding force for the dense growth of InN nanowires, displaying shortened Li ion diffusion paths, high structural stability, and fast Li+ kinetics. The InN/Au-CFs can offer stable and high-rate Li delithiation/lithiation without Li deposition, and achieve a remarkable capacity of 632.5 mAh g-1 at 0.1 A g-1 after 450 cycles and 416 mAh g-1 at a high rate of 30 A g-1. The InN nanowires as battery anodes shall hold substantial promise for fulfilling superior long-term cycling performance and high-rate capability for advanced LIBs.

Sustainable Enhanced Sodium-Ion Storage at Subzero Temperature with LiF Integration

Though layered sodium oxide materials are identified as promising cathodes in sodium-ion batteries, biphasic P3/O3 depicts improved electrochemical performance and structural stability. Herein, a coexistent P3/O3 biphasic cathode material was synthesized with "LiF" integration, verified with X-ray diffraction and Rietveld refinement analysis. Furthermore, the presence of Li and F was deduced by inductively coupled plasma-optical emission spectrometry (ICP-OES) and energy dispersive X-ray spectroscopy (EDS). The biphasic P3/O3 cathode displayed an excellent capacity retention of 85% after 100 cycles (0.2C/30 mA g^-1) at room temperature and 94% at -20 °C after 100 cycles (0.1C/15 mA g^-1) with superior rate capability as compared to the pristine cathode. Furthermore, a full cell comprising a hard carbon anode and a biphasic cathode with 1 M NaPF₆ electrolyte displayed excellent cyclic stabilities at a wider temperature range of -20 to 50 °C (with the energy density of 151.48 Wh kg^-1) due to the enhanced structural stability, alleviated Jahn-Teller distortions, and rapid Na⁺ kinetics facilitating Na⁺ motion at various temperatures in sodium-ion batteries. The detailed post-characterization studies revealed that the incorporation of LiF accounts for facile Na⁺ kinetics, boosting the overall Na storage.

Fabrication of Na-Ion Full-Cells using Carbon-Coated Na3 V2 (PO4 )2 O2 F Cathode with Conversion Type CuO Nanoparticles from Spent Li-Ion Batteries

Spent lithium-ion batteries (LIBs) offer immense potential in the form of resources such as Li, transition metals (Co, Ni, and Mn), graphite, and Cu, which can be recovered through suitable recycling procedures. The Cu-current collector is recovered from spent LIBs and converted as a copper oxide (CuO) anode for Na-ion batteries. The performance of CuO is evaluated with carboxymethyl cellulose (CMC) (CuO-C), and polyvinylidene fluoride (PVdF) (CuO-P) binders in CuO half-cell and CuO/carbon-coated Na₃ V₂ (PO₄ )₂ O₂ F (CuO/NVPOF) full-cell assemblies. The CuO-C half-cell displays superior electrochemical performance than CuO-P in terms of cycling and rate performance showing 88% more capacity. To study the stabilization and solid electrolyte interphase growth in CuO-C, an in situ impedance study is conducted. However, the full-cell, CuO-P/NVPOF displays better capacity retention during cycling with Coulombic efficiency >95% from the second cycle, whereas CuO-C/NVPOF could hardly maintain only >90%. For conversion type CuO, it is apparent that, though the CMC binder supports half-cell performance, the PVdF binder is suitable for the practical cell/full-cell configuration.

koLayered Oxide Cathode-Electrolyte Interface towards Na-Ion Batteries: Advances and Perspectives

With the ever increasing demand for low-cost and economic sustainable energy storage, Na-ion batteries have received much attention for the application on large-scale energy storage for electric grids because of the worldwide distribution and natural abundance of sodium element, low solvation energy of Na⁺ ion in the electrolyte and the low cost of Al as current collectors. Starting from a brief comparison with Li-ion batteries, this review summarizes the current understanding of layered oxide cathode/electrolyte interphase in NIBs, and discusses the related degradation mechanisms, such as surface reconstruction and transition metal dissolution. Recent advances in constructing stable cathode electrolyte interface (CEI) on layered oxide cathode are systematically summarized, including surface modification of layered oxide cathode materials and formulation of electrolyte. Urgent challenges are detailed in order to provide insight into the imminent developments of NIBs.

Suppressing the P2 - O2 phase transformation and Na+/vacancy ordering of high-voltage manganese-based P2-type cathode by cationic codoping

High-voltage and low-cost manganese-based P2-type oxides show real promise as promising cathode for sodium-ion batteries (SIBs). But the P2 - O2 phase transformation and Na⁺/vacancy ordering results in the inferior structural stability and Na⁺ diffusion coefficient, which further leads to rapid decay of capacity and poor rate capability. Herein, in consideration of the synergetic effects of dual cationic doping, electrochemically inactive Li⁺ and active Co³⁺ codoping are proposed to solve the above issues. The novel two-step doping strategy, Co doping during synthesis of precursors via coprecipitation reaction followed by Li doping during solid-state reaction, are rationally developed. As anticipated, the Li/Co codoped P2-type oxide exhibits the absence of P2 - O2 phase transformation and Na⁺/vacancy disordering, which gives rise to an outstanding cycling stability (86.7% capacity retention within 100 cycles at 0.1C) and high-rate capability (reversible capacity of 109 mAh g^-1 even at 10C). In addition, the full-cells composed of the codoped P2-type positive and hard carbon negative show high energy-density, good lifespan and high-rate property. This proposed cationic codoping provides an effective and scalable tactics for modulating the structural properties of high-voltage P2-type cathodes for advanced SIBs.