Design of Cu-Substituted O3-Type NaFe0.5 Mn0.5 O2 Cathode Materials for Sodium-Ion Batteries.

O3-type Fe/Mn-based layered oxide cathode materials with abundant reserves have a promising prospect in sodium-ion batteries. However, the electrochemical reversibility of most O3-type Fe/Mn-based oxide cathode materials is still not high enough. Herein, the effect of different Cu contents on the electrochemical properties of O3-NaFe0.50 Mn0.50 O2 materials is systematically investigated. The as-prepared NaFe0.30 Mn0.50 Cu0.20 O2 cathode achieves the synergistic optimization of the interface and bulk phase. It shows superior electrochemical performance, with an initial discharge specific capacity of 114 mAh g-1 at 0.1 C, a capacity retention rate of 94 % after 100 cycles at 0.5 C, and excellent chemical stability in air and water. In addition, the sodium ion full battery based on NaFe0.30 Mn0.50 Cu0.20 O2 cathode and hard carbon anode has a capacity retention rate of 81 % after 100 cycles. This research provides a useful approach for the preparation of low-cost and high-performance O3-type layered cathode materials.

Survival of cancer patients in Fujian, Southeast China: a population-based cancer registry study.

Survival rates are usually used to evaluate the effect of cancer treatment and prevention. No study has focused on the characteristic of population-based cancer survival in Fujian, which is regarded as one of the high-risk areas of cancer in China. This study aims to analyze the 5-year relative survival of patients in Fujian Province using population-based cancer registry data. A total of 8 population-based registries in Fujian Province reported cancer cases diagnosed in 2012-2014. Relative survival was calculated as the ratio between observed survival and expected survival. The 5-year relative survival for all cancers combined was 36.19% and the age-standardized 5-year relative survival for all patients was 31.80%. Females had higher relative survival than males (38.90% and 27.00%). The patients in urban areas had higher relative survival than those in rural areas (32.34% and 31.29%). Lung, gastric, liver, colorectal, and esophageal cancers were the five most common cancers, with 5-year relative survival below 50%. This is the first study that evaluated the population-based cancer relative survival in Fujian, China. Our study suggests that the overall survival of cancer patients in Fujian Province is poor. Furthermore, the results of this study can be used as a baseline for further research in Fujian, and provide important evidence for cancer etiology research.

Stabilized O3-Type Layered Sodium Oxides with Enhanced Rate Performance and Cycling Stability by Dual-Site Ti4+ /K+ Substitution.

High-capacity O3-type layered sodium oxides are considered one of the most promising cathode materials for the next generation of Na-ion batteries (NIBs). However, these cathodes usually suffer from low high-rate capacity and poor cycling stability due to structure deformation, native air sensitivity, and interfacial side reactions. Herein, a multi-site substituted strategy is employed to enhance the stability of O3-type NaNi0.5 Mn0.5 O2 . Simulations indicate that the Ti substitution decreases the charge density of Ni ions and improves the antioxidative capability of the material. In addition, the synergistic effect of K+ and Ti4+ significantly reduces the formation energy of Na+ vacancy and delivers an ultra-low lattice strain during the repeated Na+ extraction/insertion. In situ characterizations verify that the complicated phase transformation is mitigated during the charge/discharge process, resulting in greatly improved structure stability. The co-substituted cathode delivers a high-rate capacity of 97 mAh g-1 at 5 C and excellent capacity retention of 81% after 400 cycles at 0.5 C. The full cell paired with commercial hard carbon anode also exhibits high capacity and long cycling life. This dual-ion substitution strategy will provide a universal approach for the new rational design of high-capacity cathode materials for NIBs.