Thermal characteristic evolution of lithium-ion batteries during the whole lifecycle

This work extensively investigates the thermal characteristic evolution of lithium-ion batteries under different degradation paths,and the evolution mechanism through multi-angle characterization is revealed.Under different degradation paths,the evolution trend of temperature rise rate remains unchanged with respect to depth of discharge during the adiabatic discharge process,albeit to varying degrees of alteration.The temperature rise rate changes significantly with aging during the adiabatic discharge process under low-temperature cycling and high-rate cycling paths.The total heat generation rate,irreversible heat generation rate,and reversible heat generation rate exhibit similar evolution behavior with aging under different degradation paths.The interval range of endothermic process of reversible electrochemical reactions increases and the contribution of irreversible heat to the total heat increases with aging.To further standardize the assessment of different degradation paths on the thermal characteristics,this work introduces the innovative concept of“Ampere-hour temperature rise”.In low-temperature cycling and high-rate cycling paths,the ampere-hour temperature rise increases significantly with aging,particularly accentuated with higher discharge rates.Conversely,in high-temperature cycling and high-temperature storage paths,the ampere-hour temperature rise remains relatively stable during the initial stages of aging,yet undergoes a notable increase in the later stages of aging.The multi-angle characterization reveals distinct thermal evolution behavior under different degradation paths primarily attributed to different behavior changes of severe side reactions,such as lithium plating.The findings provide crucial insights for the safe utilization and management of lithium–ion batteries throughout the whole lifecycle.

Research on the impact of high-temperature aging on the thermal safety of lithium-ion batteries

Understanding the thermal safety evolution of lithium-ion batteries during high-temperature usage conditions bears significant implications for enhancing the safety management of aging batteries.This work investigates the thermal safety evolution mechanism of lithium-ion batteries during high-temperature aging.Similarities arise in the thermal safety evolution and degradation mechanisms for lithium-ion batteries undergoing cyclic aging and calendar aging.Employing multi-angle characterization analysis,the intricate mechanism governing the thermal safety evolution of lithium-ion batteries during high-temperature aging is clarified.Specifically,lithium plating serves as the pivotal factor contributing to the reduction in the self-heating initial temperature.Additionally,the crystal structure of the cathode induced by the dissolution of transition metals and the reductive gas generated during aging attacking the crystal structure of the cathode lead to a decrease in thermal runaway triggering temperature.Furthermore,the loss of active materials and active lithium during aging contributes to a decline in both the maximum temperature and the maximum temperature rise rate,ultimately indicating a decrease in the thermal hazards of aging batteries.

Nonlinear health evaluation for lithium-ion battery within full-lifespan

Lithium-ion batteries(LIBs), as the first choice for green batteries, have been widely used in energy storage, electric vehicles, 3C devices, and other related fields, and will have greater application prospects in the future. However, one of the obstacles hindering the future development of battery technology is how to accurately evaluate and monitor battery health, which affects the entire lifespan of battery use. It is not enough to assess battery health comprehensively through the state of health(SoH) alone, especially when nonlinear aging occurs in onboard applications. Here, for the first time, we propose a brand-new health evaluation indicator—state of nonlinear aging(SoNA) to explain the nonlinear aging phenomenon that occurs during the battery use, and also design a knee-point identification method and two SoNA quantitative methods. We apply our health evaluation indicator to build a complete LIB full-lifespan grading evaluation system and a ground-to-cloud service framework, which integrates multi-scenario data collection, multi-dimensional data-based grading evaluation, and cloud management functions. Our works fill the gap in the LIBs’ health evaluation of nonlinear aging, which is of great significance for the health and safety evaluation of LIBs in the field of echelon utilization such as vehicles and energy storage. In addition, this comprehensive evaluation system and service framework are expected to be extended to other battery material systems other than LIBs, yet guiding the design of new energy ecosystem.

Numerical Simulation of the Impact of Urban Non-uniformity on Precipitation

To evaluate the influence of urban non-uniformity on precipitation, the area of a city was divided into three categories （commercial, high-density residential, and low-density residential） according to the building density data from Landsat satel- lites. Numerical simulations of three corresponding scenarios （urban non-uniformity, urban uniformity, and non-urban） were performed in Nanjing using the WRF model. The results demonstrate that the existence of the city results in more precip- itation, and that urban heterogeneity enhances this phenomenon. For the urban non-uniformity, uniformity, and non-urban experiments, the mean cumulative summer precipitation was 423.09 mm, 407.40 mm, and 389.67 mm, respectively. Urban non-uniformity has a significant effect on the amount of heavy rainfall in summer. The cumulative precipitation from heavy rain in the summer for the three numerical experiments was 278.2 mm, 250.6 mm, and 236.5 mm, respectively. In the non- uniformity experiments, the amount of precipitation between 1500 and 2200 （LST） increased significantly. Furthermore, the adoption of urban non-uniformity into the WRF model could improve the numerical simulation of summer rain and its daily variation.

Modification of Natural Rubber Latex by Graft Copolymerization of 2-Ethylhexyl Acrylate and Methacrylic Acid

Natural rubber(NR)grafted with 2-ethylhexyl acrylate(2-EHA)and methacrylic acid(MAA,collectively NR-g-PEHA/MAA)was synthesized by emulsion polymerization.Tetraethylenepentamine and cumene hydroperoxide were used as redox initiators.The successful grafting of 2-EHA and MAA onto NR was confirmed by Fourier transform infrared spectroscopy.The morphology of the NR latex particles was observed by transmission electron microscopy.The effects of reaction temperature,initiator dosage,feeding mode,and hard monomer content on the mechanical properties of the modified NR film were investigated.Grafted polymer chains were unevenly wrapped on the outside of NR particles,and smaller particles were more easily grafted.Crosslinking was characterized using a toluene swelling method.Thermal stability and glass transition temperature were examined by differential scanning calorimetry and thermogravimetric analysis.The results showed that the thermal stability of NR-g-PEHA/MAA had been improved,and the glass transition temperature(Tg)was unchanged.

All-temperature area battery application mechanism,performance,and

Further applications of electric vehicles(EVs)and energy storage stations are limited because of the thermal sensitivity,volatility,and poor durability of lithium-ion batteries(LIBs),especially given the urgent requirements for all-climate utilization and fast charging.This study comprehensively reviews the thermal characteristics and management of LIBs in an all-temperature area based on the performance,mechanism,and thermal management strategy levels.

叶酸靶向聚合物纳米粒共传输紫杉醇和吉西他滨用于乳腺癌的治疗

针对肿瘤细胞不同信号通路的多药递药系统具有协同治疗的作用。本文中,我们开发了一种由聚-L-赖氨酸(PLL)和负载有紫杉醇/吉西他滨的聚谷氨酸(PGA-PTX和PGA-GEM)组装的叶酸(FA)修饰的聚合物多药纳米粒(FA-PMDNPs),用于FA受体靶向的乳腺癌协同治疗。PGA富含大量的羧基,为药物负载提供了充足的反应位点和负电荷。透射电子显微镜(TEM)结果表明制备的FA-PMDNPs粒径均一,为球形。溶血实验表明FA-PMDNP具有良好的生物相容性。由于乳腺癌细胞(4T1)的FA受体(FR)高表达,体外细胞活性和体内疗效结果表明FA-PMDNP比单药能够更有效地抑制乳腺癌细胞(4T1)的增殖。与单药相比,FA-PMDNPs可以有效地靶向癌细胞。因此,FA受体靶向双重载药递药系统是一种具有潜力的肿瘤纳米治疗平台。

The Aerosol Radiative Effect on a Severe Haze Episode in the Yangtze River Delta

Due to increased aerosol emissions and unfavorable weather conditions, severe haze events have occurred fre- quently in China in the last 10 years. In addition, the interaction between the boundary layer and the aerosol radiative effect may be another important factor in haze formation. To better understand the effect of this interaction, the aero- sol radiative effect on a severe haze episode that took place in December 2013 was investigated by using two WRF- Chem model simulations with different aerosol configurations. The results showed that the maximal reduction of re- gional average surface shortwave radiation, latent heat, and sensible heat during this event were 88, 12, and 37 W m2, respectively. The planetary boundary layer height, daytime temperature, and wind speed dropped by 276 m, I^C, and 0.33 m s-l, respectively. The ventilation coefficient dropped by 8%-24% for in the central and northwestern Yangtze River Delta （YRD）. The upper level of the atmosphere was warmed and the lower level was cooled, which stabilized the stratification. In a word, the dispersion ability of the atmosphere was weakened due to the aerosol radi- ative feedback. Additional results showed that the PM2.5 concentration in the central and northwestern YRD in- creased by 6-18 p.g m3, which is less than 15% of the average PM2.5 concentration during the severely polluted peri- od in this area. The vertical profile showed that the PM2.5 and PM10 concentrations increased below 950 hPa, with a maximum increase of 7 and 8 gg m-3, respectively. Concentrations reduced between 950 and 800 hPa, however, with a maximum reduction of 3.5 and 4.5 p.g rn-3, respectively. Generally, the aerosol radiative effect aggravated the level of pollution, but the effect was limited, and this haze event was mainly caused by the stagnant meteorological condi- tions. The interaction between the boundary layer and the aerosol radiative effect may have been less important than the large-scale static weather conditions for the formation of this haze episode.

Advances and Challenges of Photocatalytic Methane C—C Coupling

Methane,the main component of natural gas and shale gas,can be converted to upgraded fuels,syngas and value-added chemicals.Due to the nonpolar character of methane and large bond dissociation energy of sp^(3)C—H bond,methane conversion requires strong oxidants or acids/bases for its activation.Photocatalysis capable of inducing highly oxidative surrogates enables methane C—H bond scission at room temperature,thereby avoiding side reactions and coke formation caused by high reaction temperature.The scission of methane C—H bond generates·CH_(3)that may undergo C—C bond coupling with carbon radicals,which is a versatile way to obtain C_(2+)chemicals.Apart from the kinetically slow activation of methane C—H bond,photocatalysis also suffers from complex product distributions owing to the presence of varieties of radicals during photocatalytic methane conversion,and a low selectivity of desired C_(2+)products was achieved.In this review,we summarize the recent advances of photocatalytic methane conversion with emphasis on methane C—C bond coupling.Methods of methane C—H bond activation and radical manipulation for selective C—C bond cou-pling were discussed in detail.We hope this review may be a valuable guide of future work in photocatalytic methane C—C coupling.

An assessment of precipitation and surface air temperature over China by regional climate models

An analysis of a 20-year summer time simulation of present-day climate （1989-2008） over China using four regional climate models coupled with different land surface models is carried out. The climatic means, interannual variability, linear trends, and extremes are examined, with focus on precipitation and near surface air temperature. The models are able to reproduce the basic features of the observed summer mean precipitation and temperature over China and the regional detail due to topographic forcing. Overall, the model performance is better for temperature than that of precipitation. The models reasonably grasp the major anomalies and standard deviations over China and the five subregions studied. The models generally reproduce the spatial pattern of high interannual variability over wet regions, and low varia- bility over the dry regions. The models also capture well the variable temperature gradient increase to the north by latitude. Both the observed and simulated linear trend of precipitation shows a drying tendency over the Yangtze River Basin and wetting over South China. The models capture well the relatively small temperature trends in large areas of China. The models reasonably simulate the characteristics of extreme precipitation indices of heavy rain days and heavy precipitation fraction. Most of the models also performed well in capturing both the sign and magnitude of the daily maximum and minimum tempera- tures over China.

Functional hemispherectomy for patients with adult-onset Rasmussen’s encephalitis

Background:Surgical treatment for patients with adult-onset Rasmussen’s encephalitis(A-RE)is rarely reported.We investigated the clinical and surgical features of two patients with A-RE who underwent functional hemispherectomy.Case presentation:The data of clinical manifestations,neuroimaging,surgical treatment and surgical outcomes of two patients with A-RE was reviewed.The two patients initially presented with recurrent partial seizures or secondly generalized tonic clonic seizures.Gradually,the patients showed unilateral limb paralysis as well as chronic focal epileptic status.Both patients underwent functional hemispherectomy and achieved seizure freedom in the followup.The contralateral neurological deficits improved gradually after rehabilitation and were acceptable for the selfcare of daily living.The living quality improved prominently after surgery.Conclusions:Despite the risk of hemiplegia,functional hemispherectomy may be a choice for patients with A-RE for favorable seizure control and improved quality of life in selected patients.