Concentrated Ionic-Liquid-Based Electrolytes for High-Voltage Lithium Batteries with Improved Performance at Room Temperature

Ionic liquids (ILs) have been widely explored as alternative electrolytes to combat the safety issues associated with conventional organic electrolytes. However, hindered by their relatively high viscosity, the electrochemical performances of IL‐based cells are generally assessed at medium‐to‐high temperature and limited cycling rate. A suitable combination of alkoxy‐functionalized cations with asymmetric imide anions can effectively lower the lattice energy and improve the fluidity of the IL material. The Li/Li$_{1.2}$Ni$_{0.2}$Mn$_{0.6}$O$_{2}$ cell employing N‐N‐diethyl‐N‐methyl‐N‐(2‐methoxyethyl)ammonium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (DEMEFTFSI)‐based electrolyte delivered an initial capacity of 153 mAh g$^{-1}$ within the voltage range of 2.5–4.6 V, with a capacity retention of 65.5 % after 500 cycles and stable coulombic efficiencies exceeding 99.5 %. Moreover, preliminary battery tests demonstrated that the drawbacks in terms of rate capability could be improved by using Li‐concentrated IL‐based electrolytes. The improved room‐temperature rate performance of these electrolytes was likely owing to the formation of Li$^{+}$‐containing aggregate species, changing the concentration‐dependent Li‐ion transport mechanism

Multi-Faceted Distillation of Base-Novel Commonality for Few-shot Object Detection

Most of existing methods for few-shot object detection follow the fine-tuning paradigm, which potentially assumes that the class-agnostic generalizable knowledge can be learned and transferred implicitly from base classes with abundant samples to novel classes with limited samples via such a two-stage training strategy. However, it is not necessarily true since the object detector can hardly distinguish between class-agnostic knowledge and class-specific knowledge automatically without explicit modeling. In this work we propose to learn three types of class-agnostic commonalities between base and novel classes explicitly: recognition-related semantic commonalities, localization-related semantic commonalities and distribution commonalities. We design a unified distillation framework based on a memory bank, which is able to perform distillation of all three types of commonalities jointly and efficiently. Extensive experiments demonstrate that our method can be readily integrated into most of existing fine-tuning based methods and consistently improve the performance by a large margin

Layered Oxide Material as a Highly Stable Na‐ion Source and Sink for Investigation of Sodium‐ion Battery Materials

Investigating Na-ion battery (SIB) materials is complicated by the absence of a well-performing (reference) electrode material since sodium metal cannot be considered as a quasi-reference electrode. Taking advantage of the activity of both Ni and Mn, herein, the P2-type and Mn-rich Na$_{0.6}$Ni$_{0.22}$Al$_{0.11}$Mn$_{0.66}$O$_2$ (NAM) material, known to be an excellent positive electrode, is investigated as a negative electrode. To prove NAM stability as both positive and negative electrode, symmetric cells have been assembled without pre-sodiation, which showed a reversible capacity of 73 mA h g$^{−1}$ and a remarkable capacity retention of 82.6 % after 500 cycles. The outstanding cycling performance is ascribed to the high stability of the active material at both the highest and lowest Na-ion storage plateaus and the rather limited electrolyte decomposition and solid-electrolyte-interphase (SEI) formation occurring. The long-term stability of NAM at both electrodes enables its use as a “reference” electrode for the investigation of other positive and negative electrode materials for SIBs, resembling the role played by lithium titanate (LTO) and lithium iron phosphate (LFP) in LIBs

Do situations influence the environmentally responsible behaviors of national park visitors? Survey from Shennongjia National Park, Hubei Province, China

Natural ecological protection in protected areas involves the restriction of land use patterns and their intensity. Typically, the goal of land use is to balance environmental protection with community development. Nature education and ecological experiences in protected areas encourage visitor environmentally responsible behavior (ERB) which supports the sustainable use of land in national parks and reduces the degradation of natural environments. The existing research literature has a focus on ways of facilitating ERB through rational and external influences. However, individual behaviors are contextual and specific situations affect behavior. This research used environmental knowledge as a rational factor and situations were viewed as a moderator in stimulating ERB based on situational cognition theory. A knowledge-situation-behavior latent variable moderator model was constructed and tested with visitor survey data from Shennongjia National Park, Hubei Province, China. The findings showed that situations had a significant positive moderating effect on the relationship between environmental knowledge and ERB. Books, articles, authors and familiar people had a significant positive moderating effect on ERB, as did environmental interpretation and staff guidance. Precise measures to promote the ERB of national park visitors were proposed

Analysis of the Willingness and Factors Influencing the Residents to Choose Between Chinese Medicine and Western Medicine under the New Coronavirus Pandemic: A Study in Zhejiang Province Community Health Service Center

Objective: To understand the willingness of Chinese residents to choose between Chinese and Western medicine in the face of sudden outbreak, this study aims to investigate and analyze the willingness and factors influencing Chinese residents (taking Zhejiang Province as an example) to choose between Chinese and Western medicine under the new coronavirus pandemic. Methods: The present study performed a large-scale cross-sectional online survey among 666 random residents in Zhejiang Province. We used questionnaires to investigate the feedback form from residents seeking medical care. In addition, a multivariate logistic regression model was used to analyze the influence of gender, education, medical reimbursement, and age on the choice of Chinese and Western medicine. Results: Among the patients with mild disease, 55.9% patients chose traditional Chinese medicine, while 44.1% chose Western medicine. Moreover, the proportion of patients with severe diseases who chose traditional Chinese medicine was 7.0%, while the rate of Western medicine was 93.0%. Among the patients suffering from mild diseases, the proportion of men who chose traditional Chinese medicine (46.2%) was lower than that of women (53.8%). The usage of Chinese medicine was preferred among residents of all ages, income levels, and educational backgrounds. A total of 93.0% of patients who chose Western medicine for treatment were severely ill, and the residents with severe diseases preferred Western medicine to Chinese medicine. People with high education and young were more inclined toward Western medicine for treatment compared with Chinese medicine. It was noted that people paid most attention to the medical insurance reimbursement ratio, followed by the distance between the medical institution and the place of residence. Conclusion: The acceptance of Chinese medicine among patients has generally increased; however, gender, educational background, and income still exert a great influence on the choice between Chinese and Western medicine

La\u3csub\u3e0.6\u3c/sub\u3eSr\u3csub\u3e1.4\u3c/sub\u3eMnO\u3csub\u3e4+δ\u3c/sub\u3e Layered Perovskite Oxide: Enhanced catalytic Activity for the Oxygen Reduction Reaction

Efficient electrocatalysts for the oxygen reduction reaction (ORR) is a critical factor to influence the performance of lithium–oxygen batteries. In this study, La0.6Sr1.4MnO4+δ layered perovskite oxide as a highly active electrocatalyst for the ORR has been prepared, and a carbon-coating layer with thickness \u3c5 nm has been successfully introduced to enhance the electronic conductivity of the as-prepared oxide. XRD, XPS, Raman, SEM and TEM measurements were carried out to characterize the crystalline structure and morphology of these samples. Rotating ring-disk electrode (RRDE) technique has been used to study catalytic activities of the as-prepared catalysts for the ORR in 0.1 M KOH media. RRDE results reveal that carbon-coated La0.6Sr1.4MnO4+δ exhibits better catalytic activity for the ORR. For the carbon-coated La0.6Sr1.4MnO4+δ, the ORR proceeds predominately via a direct four electron process, and a maximum cathodic current density of 6.70 mA cm−2 at 2500 rpm has been obtained, which is close to that of commercial Pt/C electrocatalyst under the same testing conditions

Sodiophilic Current Collectors Based on MOF‐Derived Nanocomposites for Anode‐Less Na‐Metal Batteries

“Anode-less” sodium metal batteries (SMBs) with high energy may become the next-generation batteries due to the abundant resources. However, their cycling performance is still insufficient for practical uses. Herein, a metal organic frameworks (MOF)-derived copper-carbon (Cu@C) composite is developed as a sodiophilic layer to improve the Coulombic efficiency (CE) and cycle life. The Cu particles can provide abundant nucleation sites to spatially guide Na deposition and the carbon framework offer void volume to avoid volume changes during the plating/stripping process. As a result, Cu@C-coated copper and aluminum foils (denoted as Cu-Cu@C and Al-Cu@C foil) can be used as efficient current collectors for sodium plating/stripping, achieving, nearly 1600 and 240 h operation upon cycling at 0.5 mA cm$^{-2}$ and 1 mA h cm$^{-2}$, respectively. In situ dilatometry measurements demonstrate that Cu@C promotes the formation of dense Na deposits, thereby inhibiting side reactions, dendrite growth, and accumulation of dead Na. Such current collectors are employed in Na metal cells using carbon-coated Na$_{3}$V$_{2}$(PO$_{4}$)$_{3}$ (NVP/C) and copper selenides (Cu$_{2-x}$Se@C) cathodes, achieving outstanding rate capability and improved cycling performance. Most noticeably, “anode-less” Na batteries using Al-Cu@C as anode and NVP/C as cathode demonstrate promising CE as high as 99.5%, and long-term cycling life

Elucidating the Effect of Iron Doping on the Electrochemical Performance of Cobalt‐Free Lithium‐Rich Layered Cathode Materials

The eco‐friendly and low‐cost Co‐free Li1.2Mn0.585Ni0.185Fe0.03O2 is investigated as a positive material for Li‐ion batteries. The electrochemical performance of the 3 at% Fe‐doped material exhibits an optimal performance with a capacity and voltage retention of 70 and 95%, respectively, after 200 cycles at 1C. The effect of iron doping on the electrochemical properties of lithium‐rich layered materials is investigated by means of in situ X‐ray diffraction spectroscopy and galvanostatic intermittent titration technique during the first charge–discharge cycle while high‐resolution transmission electron microscopy is used to follow the structural and chemical change of the electrode material upon long‐term cycling. By means of these characterizations it is concluded that iron doping is a suitable approach for replacing cobalt while mitigating the voltage and capacity degradation of lithium‐rich layered materials. Finally, complete lithium‐ion cells employing Li1.2Mn0.585Ni0.185Fe0.03O2 and graphite show a specific energy of 361 Wh kg−1 at 0.1C rate and very stable performance upon cycling, retaining more than 80% of their initial capacity after 200 cycles at 1C rate. These results highlight the bright prospects of this material to meet the high energy density requirements for electric vehicles