Mechanical behavior analysis of high power commercial lithium-ion batteries

In application,lithium-ion cells undergo expansion during cycling.The mechanical behavior and the impact of external stress on lithium-ion battery are important in vehicle application.In this work,18 Ah high power commercial cell with Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)/graphite electrode were adopted.A commercial compress machine was applied to monitor the mechanical characteristics under different stage of charge(SOC),lifetime and initial external force.The dynamic and steady force was obtained and the results show that the dynamic force increases as the SOC increasing,obviously.During the lifetime with high power driving mode,different external force is shown to have a great impact on the long-term cell performance,with higher stresses result in higher capacity decay rates and faster impedance increases.A proper initial external force(900 N)provides lower impedance increasing.Postmortem analysis of the cells with2000 N initial force suggests a close correlation between electrochemistry and mechanics in which higher initial force leads to higher direct current internal resistance(DCIR)increase rate.In addition,for the cell with higher external force,deformation of the cathode and thicker solid electrolyte interface(SEI)film on the surface of anode and separator are observed.Porosity reduction and closure was also verified after cycles which is an obstacle to the lithium ion transferring.The largest cause of the observed capacity decline was the loss of active lithium through autopsy analysis.In addition,for the cell with higher external force,deformation of the cathode and thicker SEI film on the surface of anode and separator are observed.Porosity reduction and closure was also verified after cycles which is an obstacle to the lithium ion transferring.The largest cause of the observed capacity decline was the loss of active lithium through autopsy analysis.

School-Enterprise Cooperation in Excellent Engineer Education and Training Program at UESTC

School of Information and Software Engineering at University of Electronic Science and Technology of China(abbreviated hereafter as "SISE") joined Excellent Engineer Education and Training Program launched by Ministry of Education of China in 2011. This paper discussed nine models of school-enterprise cooperation practiced at SISE since 2011. The school-enterprise cooperation model effectively broadens the students' horizons and improves the students' practical ability and has been recognized by academic circles.

The Exploration of Talent Cultivation in Software Engineering“ Internet Plus Finance”

With the rapid development of the Internet finance industry,society has put forward urgent needs for“Internet Plus finance”composite talents,and also put forward challenges to talent cultivation in colleges and universities.To cultivate the talents in the“Internet Plus finance”,the School of Information and Software Engineering of the University of Electronic Science and Technology of China(hereinafter“the School”)begins the 10 major measures,such as the construction of training programs,the construction of the curriculum system,the construction of the faculty team,and the construction of the practice base.Meanwhile,the School works together with banks,which have cooperated for a long time,to establish the talent cultivation system in the direction of“Internet Plus finance”in the software engineering major,solving the problem of interdisciplinary talent training in the field of software engineering and finance.

Research and Exploration on the Construction of Double Qualified Teachers in Software Engineering

In order to solve the problem of insufficient integration of school-enterprise supervisors in the current school-enterprise cooperation model,this article introduces the ideas and results of the construction of a team with double-qualified instructors majored in software engineering.Specifically,the integration of production and education are carried out in three stages,i.e.,enterprise cooperation courses,enterprise internship,and graduation design(internship),by taking the software engineering major of the School of Information and Software Engineering of the University of Electronic Science and Technology of China as a case study.

The feasibility for natural graphite to replace artificial graphite in organic electrolyte with different film-forming additives

The feasibility for natural graphite(NG)to replace artificial graphite(AG)in organic electrolytes with different additives are investigated.Although the strong film-forming additives contributes to form robust solid electrolyte interphase(SEI)film on graphite particle surface,great differences in gas evolution,lithium inventory loss and other side reactions are observed.Lithium bis(oxalato)borate(Li BOB)and fluoroethylene carbonate(FEC)are found more effective and the combination shows to be more promising.In the optimized electrolyte,natural graphite anode exhibits excellent long-term cycling capability.After 800 cycles at high temperature,the capacity retention is comparable to that using artificial graphite.The mechanisms for the capacity-fading of the full cells with AG and NG anode are investigated by ICP,SEM and polarization studies.The results shows that NG electrode consumes more active lithium due to the rough surface and larger volume expansion.The rapid capacity-fading in the initial 100 cycles is related to the instability of the SEI film aroused from large volume expansion.The systematic analysis is inspiriting for the development of high performance lithium ion batteries with reduced cost.

How to Integrate Abstract Algebra and Number Theory in the Teaching of Public Key Cryptography Elegantly

Different from traditional symmetric cryptography, public key cryptography allows each user to own a pair of public/private key pair. Given the public key of one user and the data to be encrypted, a ciphertext can be generated such that only the intended user is able to recover the data using his/her private key associated with public key involved in the encryption process. To really understand the philosophy behind the public key cryptography is not an easy task and sometimes it seems somewhat difficult, if not impossible, for the beginners without the knowledge of the abstract algebra and number theory. In this paper, we introduce briefly the basic definition of public key cryptography as well as the corresponding mathematical hard problems. Besides, we explain why the mathematical backgrounds, especially abstract algebra and number theory, matter in the study of public key cryptography.

Exploration of the Training Mode of School-enterprise Collaborative AI Innovative Talents Based on PaddlePaddle

This paper takes the school-enterprise cooperation between the University of Electronic Science and Technology of China(UESTC)and Baidu(China)Co.,Ltd.as an example to build the Paddle Paddle(Sichuan)AI Education Innovation Center by enjoying the best of both UESTC and Baidu(China),and cooperating with 16 universities in Sichuan Province.With the support of this center,both the school and the enterprise successfully built a school-enterprise collaborative AI innovative talent training model,which mainly serves the universities,industries,and districts.Furthermore,this training model is able to facilitate the update of the industrial intelligence and the regional economic development in southwest China,and also provide a reference for deep integration of school-enterprise collaboration and the cultivation of innovative talents in electronic information fields.

羰基化合物作为锂离子电池有机电极材料研究进展

随着锂离子电池从便携式电子设备到大规模储能系统的应用,开发具有高能量密度、功率密度和长循环寿命的锂离子电池成为研究的重点之一.而锂离子电池的性能很大程度上取决于电极材料.目前,广泛使用的无机电极材料普遍存在容量提升有限、能耗高和成本高等缺陷.因此,开发新型电极材料至关重要.与传统无机材料相比,有机电极材料具有结构可控、资源丰富、清洁环保和成本低廉等优势,近年来得到了广泛关注.其中共轭羰基化合物以羰基为活性基团,因其结构多样、理论容量高和反应动力学快而被广泛研究.本文从正极、负极、全电池三方面,综述了目前国内外已经开展的关于羰基化合物作为锂离子电池电极材料的研究工作,评述了这些化合物的电化学性能及其具备的优势和存在的不足,并指出了有机化合物作为锂离子电池电极材料需要解决的关键问题.

Correlation between the physical parameters and the electrochemical performance of a silicon anode in lithium-ion batteries

Lithium-ion battery anode used as silicon particles were obtained from different major suppliers,and they were characterized by different spectroscopic techniques and evaluated by electrochemical experiments.Correlations between the key physical parameters and electrochemical properties of the silicon particles were investigated.Silicon particle size,surface oxygen content,-OH content and physical appearance are found to strongly influence the electrochemical properties of the Si anode.The particle size of 100 nm has great promise for the practical application of Si nanoparticles in the lithium-ion battery industry.An inverse correlation between the oxygen content and the reversible capacity or first coulombic efficiency was obtained.The-OH content by surface treatment contributes to enhanced cycling stability by the improved affinity between the Si particle and the water-soluble binder.Spherical Si particles perform better compared to irregular particles,and agglomeration dramatically decreases the cycling stability of the Si anode.Among the investigated Si particles,the sample that exhibited a reversible capacity of more than 2500 mAh g^(-1),a first coulombic efficiency of 89.26%and an excellent cycling stability,has great potential for use in the battery industry.

Preface

As the chairs of the 8th International Conference of Pioneer Computer Scientists,Engineers and Educators 2022(ICPCSEE 2022,originally ICYCSEE),it is our great pleasure to welcome you to the conference proceedings.ICPCSEE 2022 was held in Chengdu,China,during August 19-22,2022,and hosted by the Southwest Petroleum University,the University of Electronic Science and Technology of China,and the National Academy of Guo Ding Institute of Data Sciences,China.

Preface

As the chairs of the 8th International Conference of Pioneer Computer Scientists,Engineers and Educators 2022(ICPCSEE 2022,originally ICYCSEE),it is our great pleasure to welcome you to the conference proceedings.ICPCSEE 2022 was held in Chengdu,China,during August 19–22,2022,and hosted by the Southwest Petroleum University,the University of Electronic Science and Technology of China,and the National Academy of Guo Ding Institute of Data Sciences,China.