锂离子电池正极材料的研究进展

锂离子电池的应用领域日益广泛,而正极材料是锂离子电池的重要组成部分,本文介绍了锂离子电池的工作原理,综述了锂离子电池正极材料方面的研究成果。

镍钴铝锂离子电池在不同SOC区间的老化

为了探明SOC循环区间对电池老化的影响,采用镍钴铝锂离子电池为研究对象,通过循环老化与性能测试实验探究电池在不同的单SOC循环区间上的容量衰退与内阻增长的规律,采用差分电压法分析电池的老化机理.结合贝叶斯优化和长短期记忆网络,建立电池老化预测模型.根据电池在不同的变SOC循环区间工况上的实验结果,分析前、后2个SOC区间的变化方式以及SOC区间的循环顺序对电池容量衰退规律的影响.结果表明,在SOC循环区间不变时,区间的宽度越大电池的老化速度越快,可循环锂离子损失是导致电池老化的主要原因,所建立的容量衰退预测模型具有较高的精度.在SOC循环区间发生改变后电池的老化规律在短期内会发生明显的变化,当电池按照不同的SOC循环区间顺序老化时,即使在2个区间上经历相同的循环次数,电池的老化程度也不同.

Recent progress in fluorinated electrolytes for improving the performance of Li–S batteries

Lithium–sulfur(Li–S) batteries represent a "beyond Li-ion" technology with low cost and high theoretical energy density and should fulfill the ever-growing requirements of electric vehicles and stationary energy storage systems. However, the sulfur-based conversion reaction in conventional liquid electrolytes results in issues like the so-called shuttle effect of polysulfides and lithium dendrite growth, which deteriorate the electrochemical performance and safety of Li–S batteries. Optimization of conventional organic solvents(including ether and carbonate) by fluorination to form fluorinated electrolytes is a promising strategy for the practical application of Li–S batteries. The fluorinated electrolytes, owing to the high electronegativity of fluorine, possesses attractive physicochemical properties, including low melting point,high flash point, and low solubility of lithium polysulfide, and can form a compact and stable solid electrolyte interphase(SEI) with the lithium metal anode. Herein, we review recent advancements in the development of fluorinated electrolytes for use in Li–S batteries. The effect of solvent molecular structure on the performance of Li–S batteries and the formation mechanism of SEI on the cathode and anode sides are analyzed and discussed in detail. The remaining challenges and future perspectives of fluorinated electrolytes for Li–S batteries are also presented.

防爆铅酸蓄电池铲运机的优化改进设计

铲运机的工作机构往往影响着清理浮煤的效率,文章针对在前期工业性试验期间铲运机工作时的突出问题进行分析,并进行了技术改进和设计计算。详细介绍了改进后的铲运机的工作机构和部分重要器件的工作原理,并进行了铲运机铲斗装载阻力计算和倾翻油缸的浮动作用校核。经神东大柳塔煤矿使用验证得知改进工作机构后的铲运机能很好地满足井下清理浮煤和搬运货物的需要,为生产提供了极大的便利,提高了工作效率。

Latest progresses and the application of various electrolytes in high-performance solid-state lithium-sulfur batteries

With the emergence of some solid electrolytes(SSEs)with high ionic conductivity being comparable to liquid electrolytes,solid-state lithium-sulfur batteries(SSLSBs)have been widely regarded as one of the most promising candidates for the next generation of power generation energy storage batteries,and have been extensively researched.Though many fundamental and technological issues still need to be resolved to develop commercially viable technologies,SSLSBs using SSEs are expected to address the present limitations and achieve high energy and power density while improving safety,which is very attractive to large-scale energy storage systems.SSLSBs have been developed for many years.However,there are few systematic discussions related to the working mechanism of action of various electrolytes in SSLSBs and the defects and the corresponding solutions of various electrolytes.To fill this gap,it is very meaningful to review the recent progress of SSEs in SSLSBs.In this review,we comprehensively investigate and summarize the application of SSEs in LSBs to determine the differences which still exist between current progresses and real-world requirements,and comprehensively describe the mechanism of action of SSLSBs,including lithium-ion transport,interfacial contact,and catalytic conversion mechanisms.More importantly,the selection of solid electrolyte materials and the novel design of structures are reviewed and the properties of various SSEs are elucidated.Finally,the prospects and possible future research directions of SSLSBs including designing high electronic/ionic conductivity for cathodes,optimizing electrolytes and developing novel electrolytes with excellent properties,improving electrode/-electrolyte interface stability and enhancing interfacial dynamics between electrolyte and anode,using more advanced test equipment and characterization techniques to analyze conduction mechanism of Li^(+)in SSEs are presented.It is hoped that this review can arouse people’s attention and enlighten the development of functional materials and novel structures of SSEs in the next step.

车用锂离子电池失效分析与预防措施综述

为保障车用锂离子电池的安全运行和健康发展,从锂离子电池的工作机理、失效机制和失效模式3个方面进行了综述。在此基础上,汇总了相应的预防措施,并指出开发计算机失效分析模拟技术、优化锂离子开发方案,以及开发固态锂离子电池对于锂离子电池未来发展具有重要意义。

电池成形差的原因与改进措施

本文分析了电池成形率差的原因，并提出了几点改进措施。

全自动极板分选配组机机械系统设计

为了实现连续、可靠、高效的生产,通过研究铅扬尘环境下系统方案的技术要求,分析系统的工作原理,给出了以曲柄摆杆机构和曲柄滑块机构为基础的送料、取料及分选工序机械机构方案,并构建了适用于铅酸蓄电池极板生产的测试平台。测试结果表明,设计的系统运行稳定,机构动作可靠,工作效率高。

Hybrid working mechanism enables highly reversible Zn electrodes

Zn dendrite growth and water-related side reactions have been criticized to hinder actual applications of aqueous Zn-ion batteries.To address these issues,a series of Zn interfacial modifications of building solid/electrolyte interphase(SEI)and nucleation layers have been widely proposed,however,their effectiveness remains debatable.Here,we report a boron nitride(BN)/Nafion layer on the Zn surface to efficiently solve Zn problems through combining the hybrid working mechanisms of SEI and nucleation layers.In our protective layer,Nafion exhibits the SEI mechanism by blocking water from the Zn surface and providing abundant channels for rapid Zn^(2+)þtransmission,whilst BN nanosheets induce Zn deposition underneath with a preferred(002)orientation.Accordingly,dendrite-free and side-reaction-free Zn electrode with(002)deposition under the protective layer is realized for the first time,as reflected by its high reversibility with average Coulombic efficiency of 99.2%for>3000 h.The protected Zn electrode also shows excellent performance in full cells when coupling with polyaniline cathode under the strict condition of lean electrolyte addition.This work highlights insights for designing highly reversible metal electrodes towards practical applications.

Aqueous Zn-CO_(2) batteries:a route towards sustainable energy storage

In recent years,the concept of rechargeable aqueous Zn–CO_(2) batteries has attracted extensive attention owing to their dual functionality of power supply and simultaneous conversion of CO_(2) into value-added chemicals or fuels.The state-of-the-art research has been mainly focused on the exploration of working mechanisms and catalytic cathodes but hardly applies an integrative view.Although numerous studies have proven the feasibility of rechargeable aqueous Zn–CO_(2) batteries,challenges remain including the low CO_(2) conversion efficiency,poor battery capacity,and low energy efficiency.This review systematically summarizes the working principles and devices,and the catalytic cathodes used for Zn–CO_(2) batteries.The challenges and prospects in this field are also elaborated,providing insightful guidance for the future development of rechargeable aqueous Zn–CO_(2) batteries with high performance.

锂离子电池高能量密度正极材料的研究进展

日益增长的清洁可持续能源取代传统化石燃料的需求,推动了二次电池的发展.然而,商业化成功的锂离子电池仍面临成本和安全方面的重大挑战,因此迫切需要寻找具有更高能量密度和更好安全性的二次电池.从材料角度,层状过渡金属氧化物由于其高理论容量、高工作电压和低制造成本而被认为是有前途的高能量密度正极材料.然而,由于存在电化学稳定性问题,层状过渡金属氧化物仍未充分发挥其应用的潜力.本文首先综述了锂离子电池具有代表性的高能量密度正极材料,重点讨论了钴酸锂正极材料的发展历程和结构特性,介绍了其工作机理和失效机制,总结并分析了相应的改性策略及其在增强电化学稳定性方面的表现;然后介绍了钴酸锂高能量密度正极材料的工程应用现状和改进措施;最后展望了高能量密度可充电电池的发展前景.

金属锂枝晶生长机制及抑制方法

金属锂负极以极高的容量(3860 m Ah·g^(-1))和最负的电势(-3.040 V vs标准氢电极)而被称为二次锂电池"圣杯"电极。以金属锂为负极的金属锂电池是极具前景的下一代高比能电池(比如锂硫和锂氧电池等)。然而,在锂离子反复沉积和析出过程中,金属锂负极表面容易生长出锂枝晶,并发生粉化,大大降低了电池的利用率,造成安全隐患,缩短电池使用寿命。本综述针对金属锂的枝晶问题开展评述。首先介绍金属锂负极的工作原理和存在的挑战;其次,评述金属锂负极的枝晶生长模型;再次,总结近年来针对抑制金属锂负极枝晶生长的研究进展。最后,总结全文并对金属锂负极的研究进行了展望。该综述尝试总结金属锂负极近些年在理论和技术上的进步,并为金属锂电池的实用化研究提供借鉴。

An in-depth mechanistic insight into the redox reaction and degradation of aqueous Zn-MnO_(2) batteries

Rechargeable aqueous Zn/MnO_(2)batteries raise massive research activities in recent years. However, both the working principle and the degradation mechanism of this battery chemistry are still under debate. Herein, we provide an in-depth electrochemical and structural investigation on this controversial issue based on α-MnO_(2)crystalline nanowires. Mechanistic analysis substantiates a two-electron reaction pathway of Mn2+/Mn4+redox couple from part of MnO_(2)accompanying with a reversible precipitation/dissolution of flaky zinc sulfate hydroxide(ZSH) during the discharge/charge processes. The formation of the ZSH layer is double-edged, which passivates the deep dissolution of MnO_(2)upon discharging,but promotes the electrochemical deposition kinetics of active MnO_(2)upon charging. The cell degradation originates primarily from the corrosion failure of metallic zinc anode and the accumulation of irreversible ZnMn2O_(4)phases on the cathode. The addition of MnSO_(4)to the electrolyte could afford supplementary capacity contribution via electro-oxidation of Mn2+. However, a high MnSO_(4)concentration will expedite the cell failure by corroding the metallic zinc anodes. The present study will shed a fundamental insight on developing new strategies toward practically viable Zn/MnO_(2)batteries.

锂离子电池的工作原理与关键材料

锂离子电池具有能量密度高、自放电小和循环寿命长等优点,被广泛用于便携式电子设备和电动汽车等方面,不断推动着社会朝着智能化和清洁化方向发展。简要阐述了锂离子电池的发展历程和工作原理,从材料结构和储锂机制方面对正极材料和负极材料进行分类并综述其性能特点与研究现状,介绍了液态电解液中锂盐、溶剂、添加剂以及固态电解质在锂离子电池中的作用,重点讨论了锂离子全电池的应用和安全问题,最后对锂离子电池的发展趋势进行了总结和展望。相信随着这些重点、难点技术和关键材料的突破,性能更加优异的锂离子电池必定会更好地造福人类。

In situ atomic-scale observation of size-dependent (de) potassiation and reversible phase transformation in tetragonal FeSe anodes

Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant challenge.In addition,the reaction mecha-nisms and origins of enhanced performance remain elusive.Here,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron micros-copy.We found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is size-dependent.Apparent expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized nanoflakes.The significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element analysis.Despite the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon depotassiation.In particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural integrity.This article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation dynamics.Moreover,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs.

双动力系统巷道修复机简介

针对电动版巷道修复机受电缆长度限制、无法实现长距离工作,以及柴油版巷道修复机运行噪声大、污染巷道等问题,研制了一种防爆动力电池与动力电缆共同作用的双动力系统巷道修复机。该巷道修复机行走机构运行时,防爆动力电池提供动力,不受电缆长度限制,满足其长距离行走要求;工作装置运行时,井下动力电为动力,满足高强度工作和环境要求。它能够实现工作装置旋转 180°、左右摆动 35°以及俯仰 15°等动作,完成破岩、卧底、挖掘以及平整等巷道修复工作。