Safer Lithium-Ion Batteries from the Separator Aspect:Development and Future Perspectives

With the rapid development of lithium-ion batteries(LIBs),safety problems are the great obstacles that restrict large-scale applications of LIBs,especially for the high-energy-density electric vehicle industry.Developing component materials(e.g.,cathode,anode,electrolyte,and separator)with high thermal stability and intrinsic safety is the ultimate solution to improve the safety of LIBs.Separators are crucial components that do not directly participate in electrochemical reactions during charging/discharging processes,but play a vital role in determining the electrochemical performance and safety of LIBs.In this review,the recent advances on traditional separators modified with ceramic materials and multifunctional separators ranging from the prevention of the thermal runaway to the flame retardant are summarized.The component–structure–performance relationship of separators and their effect on the comprehensive performance of LIBs are discussed in detail.Furthermore,the research challenges and future directions toward the advancement in separators for high-safety LIBs are also proposed.

Boosting lithium batteries under harsh operating conditions by a resilient ionogel with liquid-like ionic conductivity

New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh operating conditions. Here we report on the synthesis of a unique ionogel electrolyte for abuse-tolerant lithium batteries. A hierarchically architected silica/polymer scaffold is designed and fabricated through a facile soft chemistry route, which is competent to confine ionic liquids with superior uptake ability (92.4 wt%). The monolithic ionogel exhibits high conductivity and thermal/mechanical stability, featuring high-temperature elastic modulus and dendrite-free lithium cycling. The Li/LiFePO_(4) pouch cells achieve outstanding cyclability at different temperatures up to 150 ℃, and can sustain cutting, crumpling, and even coupled thermal–mechanical abuses. Moreover, the solid-state lithium batteries with LiNi_(0.60)Co_(0.20)Mn_(0.20)O_(2), LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2), and Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) cathodes demonstrate excellent cycle performances at 60 ℃. These results indicate that the resilient and high-conductivity ionogel electrolyte is promising to realize high-performance lithium batteries with high energy density and safety.

Highly efficient H-bonding charge-transfer complex for microsupercapacitors under extreme conditions of low temperatures

Owing to sluggish ionic mobility at low temperatures, supercapacitors, as well as other energy-storage devices, always suffer from severe capacity decay and even failure under extreme low-temperature circumstances. Solar-thermal-enabled self-heating promises an attractive approach to overcome this issue.Here, we report a unique H-bonding charge-transfer complex with a high photothermal conversion efficiency of 79.5% at 405 nm based on chloranilic acid and albendazole. Integrated with a microsupercapacitor, the chloranilic acid-albendazole complex(CAC) film prompts an apparent temperature increase of 22.7 °C under 1 sun illumination at-32.6 °C, effectively elevating the working temperature of devices.As a result, the rate capability of the microsupercapacitor has been significantly improved with a 17-fold increase in capacitance at a current density of 60 μA cm^(-2), leading to outstanding low-temperature performances. Importantly, the integrated device is capable of working at a low temperature of-30 °C in the open air, which demonstrates the potential of CAC in practical applications for low-temperature ultracapacitive energy-storage devices.

钠离子电容器负极的双功能补钠研究

电极的首次库伦效率低是限制快充钠离子电容器规模化使用的原因之一,这主要源于电解液的不可逆分解以及电极材料造成的不可逆损失.我们选取高倍率特性的Nb_(2)O_(5)负极材料作为研究对象,采用钠萘/2-甲基-四氢呋喃作为预钠化剂,发展了一种简单且可精确调控的双功能预钠化剂,实现了预活化,获得了高稳定循环的NaxNb_(2)O_(5)电极,从而补偿了钠在材料中的不可逆吸收.研究发现,预钠化过程同时抵消了电解液分解所产生的损失,有利于在电极/电解液界面形成坚固的富含无机物的固体电解质界面膜.通过补偿Nb_(2)O_(5)负极的体相与界面的钠损失,构建了稳定且具有高能量密度的钠离子电容器.本研究为调控储钠电极的首次库伦效率及其在下一代钠离子电容器中的应用提供了新方法.

基于共溶剂分子间相互作用和阳离子溶剂化的耐低温、长寿命锌离子电容器(英文)

近年来,水系锌基储能器件引起了人们极大的关注.然而,锌负极中不可控的枝晶生长限制了其循环寿命.另外,水系电解液在零度以下冻结导致较差的低温性能,限制了其在寒冷地区的实际应用.以锌离子混合电容器为例,本文报道了通过调节水/乙二醇共溶剂电解液来构建耐低温、长寿命的锌离子混合电容器.通过调控共溶剂的组分,系统探索了水和乙二醇分子间的氢键作用以及阳离子溶剂化对电化学性能的影响.结果表明,硫酸锌/水/乙二醇(65%)电解液在低温下具备较高的离子电导率,并且可以有效地防止锌负极中枝晶的形成.组装的锌离子混合电容器具有长循环稳定性,能够在零下40℃的极端低温条件下工作.该锌离子混合电容器成本低,具有较好的抗冻特性,有望应用于下一代电化学储能领域.

（G, s）-Transitive Graphs of Valency 7

让 X 是一张有限的简单的未受指导的图和 G X 的一个自守组。如果 G 在 s 弧上然而并非在上是及物的(s+1 ) 那么， X 被打电话给的弧(G， s ) 及物。让 X 一连接(G， s ) 主要原子价 p 的及物的图，和 G v 在 G 的顶点 v V (X) 的顶点 stabilizer。为盒子 p=3， G v 被 Djokovi 和米勒决定了在[立方的图的自守的常规组， J。Combin。理论(重量的单位。B ) 29 (1980 ) 195 - 230 ] 。为盒子 p=5， G v 被郭和冯给了在里面[五价的 s 及物的图上的笔记，分离 Math.312 (2012 ) 2214 - 2216 ] 。在这份报纸，我们处理盒子 p=7 并且决定顶点 stabilizer G v 。

Using unmanned aerial vehicles with thermal-image acquisition cameras for animal surveys:a case study on the Sichuan snub-nosed monkey in the Qinling Mountains

Following significant developments in technology,alternative devices have been applied in fieldwork for animal and plant surveys.Thermal-image acquisition cameras installed on unmanned aerial vehicles(UAVs)have been used in animal surveys in the wilderness.This article demonstrates an example of how UAVs can be used in high mountainous regions,presenting a case study on the Sichuan snub-nosed monkey with a detection rate of 65.19%for positive individual identification.It also presents a model that can prospectively predict population size for a given animal species,which is based on combined initial work using UAVs and traditional surveys on the ground.A great potential advantage of UAVs is significantly shortening survey procedures,particularly for areas with high mountains and plateaus,such as the Himalayas,the Qinghai-Tibet Plateau,Hengduan Mountains,the Yunnan-Gui Plateau and Qinling Mountains in China,where carrying out a traditional survey is extremely difficult,so that species and population surveys,particularly for critically endangered animals,are largely absent.This lack of data has impacted the management of endangered animals as well as the formulation and amendment of conservation strategies.

Lithium-ion insertion kinetics of Na-doped Li2TiSiO5 as anode materials for lithium-ion batteries

Li2TiSiO5 receives much interest recently in lithium-ion battery anodes because of its attractive Liinsertion/extraction potential at 0.28 V(vs. Li+/Li), which bridges the potential gap between graphite and Li4 Ti5 O12. However, Li2TiSiO5 suffers from the low intrinsic electronic conductivity and sluggish Liion transfer kinetics. In this work, we report lithium-ion insertion kinetics of Li2TiSiO5 by Na doping,achieving high-rate capability. Rietveld refinement of X-ray diffraction results reveals that Na doping can enlarge the space of Li slabs, thus reducing the Li-ion transfer barrier and enhancing the Li-ion diffusion kinetics. According to first-principles calculations, Na doping can tune the band structure of Li2TiSiO5 from indirect to direct band, leading to improved electronic conductivity and electrochemical performance. In particular, the Na-doped Li2TiSiO5(Li1.95 Na(0.05)TiSiO5) electrode exhibits outstanding rate capability with a high capacity of 101 m A h g^(-1) at 5 A g^(-1) and superior cyclability with a reversible capacity of 137 m A h g^(-1) under 0.5 A g^(-1) over 150 cycles.

The application of the Internet of Things to animal ecology

For ecologists,understanding the reaction of animals to environmental changes is critical.Using networked sensor technology to measure wildlife and environmental parameters can provide accurate,real-time and comprehensive data for monitoring,research and conservation of wildlife.This paper reviews:(i)conventional detection technology;(ii)concepts and applications of the Internet of Things(IoT)in animal ecology;and(iii)the advantages and disadvantages of IoT.The current theoretical limits of IoT in animal ecology are also discussed.Although IoT offers a new direction in animal ecological research,it still needs to be further explored and developed as a theoretical system and applied to the appropriate scientific frameworks for understanding animal ecology.

Specialized digestive adaptations within the hindgut of a colobine monkey

In mammal herbivores,fiber digestion usually occurs predominantly in either the foregut or the hindgut.Reports of mechanisms showing synergistic function in both gut regions for the digestion of fiber and other nutrients in wild mammals are rare because it requires integrative study of anatomy,physiology,and gut microbiome.Colobine monkeys(Colobinae)are folivorous,with high-fiber foods fermented primarily in their foreguts.

A newly-found pattern of social relationships among adults within one-male units of golden snub-nosed monkeys(Rhinopithecus roxenalla)in the Qinling Mountains,China

Group living provides various advantages to individuals in regards to protection avoidance,intergroup competition,productive success and social information.Stable one-male units(OMUs)consist of relationships between the adult females and the resident male as well as the relationships among adult females.Based on continuous observation of a reproductive group of golden snub-nosed monkeys(Rhinopithecus roxellana)in the Qinling Mountains,we analyzed the relationships among adult individual dyads within 4 OMUs.The results indicated that in golden snub-nosed monkey societies,females not only had no strong tendency to build a relationship with the resident male in the OMU but also had no strong tendency to build relationships with other females in the OMU.In comparison with hamadryas(Papio hamadryas)and gelada baboons(Theropithecus gelada),the relationships within golden snub-nosed monkeys OMUs showed neither the star-shaped pattern observed in hamadryas baboons nor the net-shaped pattern observed in gelada baboons.We concluded that the relationships within golden snub-nosed monkey OMUs indicated a third pattern in nonhuman primate societies.Future research is required to determine the potential mechanisms for such a pattern.

Population structure of the golden snub-nosed monkey Rhinopithecus roxellana in the Qinling Mountains, central China

Environmental barriers and habitat fragmentation can restrict gene flow,leading to genetic divergence among animal populations.The golden snub-nosed monkey,Rhinopithecus roxellana,is endemic to China,and rang­es across 4 provinces.However,over the past 40 years its populations have become fragmented.We investigat­ed the genetic diversity,demographic history and population structure of R.roxellana in 5 reserves in one of its strongholds,the Qinling Mountain forests of Shaanxi.We collected genetic material from 11 monkey bands(a group of individuals containing multiple 1-male units)with a total of 428 samples genotyped at 20 microsatel­lite loci.Allelic richness and heterozygosity suggested a relatively high level of intra-band genetic diversity.We found no evidence of any genetic bottleneck in these R.roxellana populations.AMOVA and Bayesian cluster analysis revealed that R.roxellana in the 5 reserves are highly structured and form at least 3 distinct subpopula­tions.These subpopulations concur with major topographical features in the study area,such as mountain ridg­es,suggesting that dispersal of R.roxellana may be restricted by geographical barriers.