Thermal runaway propagation behavior of the Cell-to-Pack battery system

Structurally compact battery packs significantly improve the driving range of electric vehicles.Technologies like Cell-to-Pack increase energy density by 15%-20%.However,the safety implications of multiple tightly-packed battery cells still require in-depth research.This paper studies thermal runaway propagation behavior in a Cell-to-Pack system and assesses propagation speed relative to other systems.The investigation includes temperature response,extent of battery damage,pack structure deformation,chemical analysis of debris,and other considerations.Results suggest three typical patterns for the thermal runaway propagation process:ordered,disordered,and synchronous.The synchronous propagation pattern displayed the most severe damage,indicating energy release is the largest under the synchronous pattern.This study identifies battery deformation patterns,chemical characteristics of debris,and other observed factors that can both be applied to identify the cause of thermal runaway during accident investigations and help promote safer designs of large battery packs used in large-scale electric energy storage systems.

Quantitative analysis of C, Si, Mn, Ni, Cr and Cu in low-alloy steel under ambient conditions via laser-induced breakdown spectroscopy

A diode-pumped solid-state laser （DPSSL） with a high energetic stability and long service life is applied to ablate the steel samples instead of traditional Nd：YAG laser pumped by a xenon lamp, and several factors, such as laser pulse energy, repetition rate and argon flow rate, that influence laser-induced breakdown spectroscopy （LIBS） analytical performance are investigated in detail. Under the optimal experiment conditions, the relative standard deviations for C, Si, Mn, Ni, Cr and Cu are 3.3%-8.9%, 0.9%-2.8%, 1.2%-4.1%, 1.7%-3.0%, 1.1%-3.4% and 2.5%-8.5%, respectively, with the corresponding relative errors of 1.1%-7.9%, 1.0%-6.3%, 0.4%-3.9%, 1.5%-6.3%, 1.2%-4.0% and 1.2%-6.4%. Compared with the results of the traditional spark discharge optical emission spectrometry technique, the analytical performance of LIBS is just a little inferior due to the less stable laser-induced plasma and smaller amount of ablated sample by the laser. However, the precision, detection limits and accuracy of LIBS obtained in our present work were sufficient to meet the requirements for process analysis. These technical performances of higher stability of output energy and longer service life for DPSSL, in comparison to the Q-switch laser pumped by xeon lamp, qualify it well for the real time online analysis for different industrial applications.

Catalytic combustion of methane over Pd/SnO_2 catalysts

SnO2‐supported Pd catalysts were prepared and the effects of the support calcination temperature on the subsequent catalytic activity during methane combustion were investigated.The physicochemical properties of the Pd/SnO2were characterized by X‐ray diffraction,high‐resolution transmission electron microscopy,X‐ray photoelectron spectroscopy,oxygen temperature‐programmed desorption and CH4temperature‐programmed surface reaction.Only crystalline Pd species were found on the catalysts fabricated from the supports calcined above800°C.It was also determined that lattice geometry matching between PdO and SnO2in the catalyst made with a support calcined at1200°C facilitated oxygen activation from SnO2to vacant oxygen sites on the PdO/Pd surface via the back‐spillover of oxygen.This effect in turn enhanced the catalytic combustion process.The activity of this material was clearly increased compared with the catalysts that did not exhibit lattice matching between the PdO and support.

Recent progress in the development of smart supercapacitors

Recently,with the continuous development of human society and the continuous innovation of technologies,the intelligence era has arrived.Various intelligent electronic devices continue to be developed,in which flexible wearable electronic devices are highly favored by people.To meet the requirements of the normal operation of intelligent devices,the key point lies in the development of new smart energy storage devices.Accordingly,smart supercapacitors have been widely focused on and studied by researchers recently with the introduction of intelligent functions,such as electrochromism,self‐healing,and shape memory,into supercapacitors to broaden their application fields and promote their smart development.This can meet not only people's energy needs but also people's diverse personality needs and make our life more convenient,fast,and more intelligent than ever.Therefore,it is very important to summarize related work on smart supercapacitors.Although researchers have performed much research on smart supercapacitors,there is still little literature summary on the related work of different smart supercapacitors.Accordingly,this paper mainly introduces the research progress on electrochromic,self‐healing,shape memory,and self‐charging smart supercapacitors in recent years and discusses the development prospects and challenges of smart supercapacitors.

Oxygen-modulated metal nitride clusters with moderate binding ability to insoluble Li_(2)S_(x) for reversible polysulfide electrocatalysis

Multiphase sulfur redox reactions with advanced homogeneous and heterogeneous electrochemical processes in lithium–sulfur(Li–S)batteries possess sluggish kinetics.The slow kinetics leads to significant capacity decay during charge/discharge processes.Therefore,electrocatalysts with adequate sulfurredox properties are required to accelerate reversible polysulfide conversion in cathodes.In this study,we have fabricated an oxygen-modulated metal nitride cluster(C-MoN_(x)-O)that has a moderate binding ability to the insoluble Li_(2)S_(x)for reversible polysulfide electrocatalysis.A Li–S battery equipped with CMoN_(x)-O electrocatalyst displayed a high discharge capacity of 875 mAh g^(-1)at 0.5 C.The capacity decay rate of each cycle was only 0.10%after 280 cycles,which is much lower than the control groups(C-MoO_(x):0.16%;C-MoN_(x):0.21%).Kinetic studies and theoretical calculations suggest that C-MoN_(x)-O electrocatalyst presents a moderate binding ability to the insoluble Li_(2)S_(2)and Li_(2)S when compared to the C-MoO_(x)and C-MoN_(x)surfaces.Thus,the C-MoN_(x)-O can effectively immobilize and reversibly catalyze the solid–solid conversion of Li_(2)S_(2)–Li_(2)S during charge–discharge cycling,thus promoting reaction kinetics and eliminating the shuttle effect.This study to design oxygen-doped metal nitrides provides innovative structures and reversible solid–solid conversions to overcome the sluggish redox chemistry of polysulfides.

CEO能力、CEO权力与CEO薪酬

学术界认为高管薪酬是解决管理层和股东之间的代理问题的核心治理机制。本文以2010—2019年沪深A股非金融、保险上市公司为研究样本,实证研究了CEO能力、CEO权力与CEO薪酬的关系。研究结果表明:CEO能力越高,获得的CEO薪酬越多,CEO薪酬溢价是CEO能力的体现,符合管理层能力观。采用CEO能力的区域均值作为工具变量,解决了内生性问题,并通过了稳健性检验。进一步研究结果表明,与国有企业相比,非国有企业CEO能力对CEO薪酬的正向作用更加显著;与市场化程度高的地区相比,在市场化程度低的地区,CEO能力对CEO薪酬的正向影响更加显著,研究结论进一步丰富了高管薪酬和CEO能力的相关研究。

社会责任报告与企业系统风险应对

社会责任报告作为信息披露机制,已吸引了社会各方的关注,本文选取2009—2014年沪深A股上市企业为研究样本,从企业披露社会责任报告的经济后果的角度来研究企业社会责任报告与企业系统风险之间的关系,研究结果表明:企业披露社会责任报告能有效应对企业面临的系统风险,而且披露的社会责任质量越高,对企业系统风险的应对作用越显著。最后,在结论的基础上,从政府部门、社会责任报告专业评级机构、企业自身三个层面提出了政策建议。