A Cable-Stayed Honeycomb Superstructure to Improve the Stability of Li-Rich Materials via Inhibiting Interlaminar Lattice Strain.

In layered Li-rich materials, over stoichiometric Li forms an ordered occupation of LiTM in transition metal (TM) layer, showing a honeycomb superstructure along [001] direction. At the atomic scale, the instability of the superstructure at high voltage is the root cause of problems such as capacity/voltage decay of Li-rich materials. Here a Li-rich material with a high Li/Ni disorder is reported, these interlayer Ni atoms locate above the honeycomb superstructure and share adjacent O coordination with honeycomb TM.

Carbon-reinforced NiS/TiCT MXene composite as an anode for superior-performance lithium-ion capacitors.

Lithium ion capacitors (LICs) are a new generation of energy storage devices that combine the super energy storage capability of lithium ion batteries with the satisfactory power density of supercapacitors. The development of high-performance LICs still faces great challenges due to the unbalanced reaction kinetics at the anode and cathode. Therefore, it is an inevitable need to enhance the electron/ion transfer capability of the anode materials.

Surface chemical heterogeneous distribution in over-lithiated LiCoO electrodes.

In commercial Li-ion batteries, the internal short circuits or over-lithiation often cause structural transformation in electrodes and may lead to safety risks. Herein, we investigate the over-discharged mechanism of LiCoO/graphite pouch cells, especially spatially resolving the morphological, surface phase, and local electronic structure of LiCoO electrode. With synchrotron-based X-ray techniques and Raman mapping, together with spectroscopy simulations, we demonstrate that over-lithiation reaction is a surface effect, accompanied by Co reduction and surface structure transformation to LiCoO/CoO/CoO/LiO-like phases.

Constructing Stable Anion-Tuned Electrode/Electrolyte Interphase on High-Voltage Na V (PO ) F Cathode for Thermally-Modulated Fast-Charging Batteries.

Constructing stable electrode/electrolyte interphase with fast interfacial kinetics is vital for fast-charging batteries. Herein, we investigate the interphase that forms between a high-voltage Na V (PO ) F cathode and the electrolytes consisting of 3.0, 1.

Pseudocapacitive Crystalline MnCoO and Amorphous MnCoS Core/Shell Heterostructure with Graphene for High-Performance K-Ion Hybrid Capacitors.

Potassium-ion capacitors (KICs) have received a surge of interest because of their higher reserves and lower costs of potassium than lithium. However, the cycle performance and capacity of potassium devices have been reported to be unsatisfactory. Herein, a unique crystalline MnCoO and amorphous MnCoS core/shell nanoscale flower structure grown on graphene (MCO@MCS@rGO) was synthesized by a two-step hydrothermal process and demonstrated in KICs.

Enhancing Na-Ion Storage at Subzero Temperature via Interlayer Confinement of Sn.

Sluggish kinetics and limited reversible capacity present two major challenges for layered titanates to achieve satisfactory sodium-ion storage performance at subzero-temperatures (subzero-T). To facilitate sodiation dynamics and improve reversible capacity, we proposed an additive-free anode with Sn(II) located between layers. Sn-5s in interlayer-confining Sn(II), which has a larger negative charge, will hybridize with O-2p to trigger charge redistribution, thereby enhancing electronic conductivity.

Pseudocapacitance of TiO /CNT Anodes for High-Performance Quasi-Solid-State Li-Ion and Na-Ion Capacitors.

It is challenging for flexible solid-state hybrid capacitors to achieve high-energy-high-power densities in both Li-ion and Na-ion systems, and the kinetics discrepancy between the sluggish faradaic anode and the rapid capacitive cathode is the most critical issue needs to be addressed. To improve Li-ion/Na-ion diffusion kinetics, flexible oxygen-deficient TiO /CNT composite film with ultrafast electron/ion transport network is constructed as self-supported and light-weight anode for a quasi-solid-state hybrid capacitor. It is found that the designed porous yolk-shell structure endows large surface area and provides short diffusion length, the oxygen-deficient composite film can improve electrical conductivity, and enhance ion diffusion kinetic by introducing intercalation pseudocapacitance, therefore resulting in advance electrochemical properties.