An Intrinsic Stable Layered Oxide Cathode for Practical Sodium-Ion Battery: Solid Solution Reaction, Near-Zero-Strain and Marvelous Water Stability.

Non-aqueous solvents, in particular N,N-dimethylaniline (NMP), are widely applied for electrode fabrication since most sodium layered oxide cathode materials are readily damaged by water molecules. However, the expensive price and poisonousness of NMP unquestionably increase the cost of preparation and post-processing. Therefore, developing an intrinsically stable cathode material that can implement the water-soluble binder to fabricate an electrode is urgent. Herein, a stable nanosheet-like Mn-based cathode material is synthesized as a prototype to verify its practical applicability in sodium-ion batteries (SIBs). The as-prepared material displays excellent electrochemical performance and remarkable water stability, and it still maintains a satisfactory performance of 79.6% capacity retention after 500 cycles even after water treatment. The in situ X-ray diffraction (XRD) demonstrates that the synthesized material shows an absolute solid-solution reaction mechanism and near-zero-strain. Moreover, the electrochemical performance of the electrode fabricated with a water-soluble binder shows excellent long-cycling stability (67.9% capacity retention after 500 cycles). This work may offer new insights into the rational design of marvelous water stability cathode materials for practical SIBs.

Compressive Property of Additively-Manufactured Micro-Architectures with X-Type Lattice Unit Cell.

In this paper, novel micro-architectures with X-type lattice unit cell (namely, face-centered cubic (FCC), and X-type) are constructed and prepared by additive manufacturing technology. The compression behaviors of micro-architectures are explored in detail by experimental measurement and theoretical prediction. It is found that the strength of FCC micro-lattice structure is higher than that of the X-type micro-lattice structure with the same relative density. The X-type micro-lattice structure exhibits a zero Poisson's ratio during compression deformation. In addition, the compressive strength and energy absorption efficiency of proposed micro-architectures shows a higher advantage over other previously cellular materials in a map for material selection.

Contrast-Enhanced Ultrasound Evaluation of Mifepristone for Treatment of Low-Risk Cesarean Scar Pregnancy.

Purpose: The effect of mifepristone for treatment of low-risk cesarean scar pregnancy (CSP) was monitored by contrast-enhanced ultrasound (CEUS). Methods: Data were collected from 23 CSP patients with a 10-point risk score <5 (low-risk CSP) and from 23 intrauterine pregnancy (IUP) patients with a scar from a previous cesarean delivery. All patients were prescribed 75 mg mifepristone daily for 2 days and underwent transvaginal CEUS before and after administration of mifepristone. On the third day, uterine curettage was performed after transvaginal CEUS. Arrival time (AT), peak intensity (PI), and area under the curve (AUC) around the gestational sac were monitored by CEUS before and after application of mifepristone, and the rate of effective treatment was compared between the two patient groups. Results: No patients experienced side effects from either the CEUS procedure or the mifepristone treatment. Changes in AT, PI, and AUC index from before vs. after mifepristone treatment did not differ significantly between the two groups (all p values >0.05). There was also no significant difference in the rate of effective treatment between the two groups (95.65% in the CSP group vs. 100% in the IUP group; p > 0.05). Conclusions: Based on monitoring by CEUS, the effect of mifepristone in low-risk CSP was comparable to that in IUP.

Enhancing the high rate capability and cycling stability of LiMn2O4 by coating of solid-state electrolyte LiNbO3.

To study the influence of solid-state electrolyte coating layers on the performance of cathode materials for lithium-ion batteries in combination with organic liquid electrolyte, LiNbO3-coated Li1.08Mn1.92O4 cathode materials were synthesized by using a facile solid-state reaction method. The 0.06LiNbO3-0.97Li1.08Mn1.92O4 cathode exhibited an initial discharge capacity of 125 mAh g(-1), retaining a capacity of 119 mAh g(-1) at 25 °C, while at 55 °C, it exhibited an initial discharge capacity of 130 mAh g(-1), retaining a capacity of 111 mAh g(-1), both at a current density of 0.5 C (where 1 C is 148 mAh g(-1)). Very good rate capability was demonstrated, with the 0.06LiNbO3-0.97Li1.08Mn1.92O4 cathode showing more than 85% capacity at the rate of 50 C compared with the capacity at 0.5 C. The 0.06LiNbO3-0.97Li1.08Mn1.92O4 cathode showed a high lithium diffusion coefficient (1.6 × 10(-10) cm(2) s(-1) at 55 °C), and low apparent activation energy (36.9 kJ mol(-1)). The solid-state electrolyte coating layer is effective for preventing Mn dissolution and maintaining the high ionic conductivity between the electrode and the organic liquid electrolyte, which may improve the design and construction of next-generation large-scale lithium-ion batteries with high power and safety.