近年来,过渡金属氧化物已被认为是最有希望代替贵金属作为锂氧(Li-O2)电池阴极催化剂的材料。本文研究了一种由静电纺纤维煅烧后自发形成的MnO纳米颗粒作为Li-O2电池的高效催化剂。物性表征的结果显示成功合成了平均粒径为61.82 nm的MnO纳米颗粒,为立方晶系结构,作为Li-O2电池阴极在500次循环中表现出优异的循环稳定性,首次充电过电位为0.46 V,在500 mA·g−1的高电流密度下实现了1000 h的稳定循环,优于大多数已报道的用于Li-O2电池的MnOx催化剂。In recent years, transition metal oxides have been considered the most promising materials to replace precious metals as cathode catalysts for lithium-oxygen batteries. This study investigates MnO nanoparticles that spontaneously form after calcining electrospun fibers as an efficient catalyst for lithium-oxygen (Li-O2) batteries. Physical characterization shows that MnO nanoparticles with an average particle size of 61.82 nm and a cubic crystal structure were successfully synthesized. They exhibit excellent cycling stability as a cathode in Li-O2 batteries, enduring over 500 cycles with an initial overpotential of 0.46 V. Concurrent, they also achieve stable cycling for 1000 hours at a high current density of 500 mA·g−1, outperforming most reported catalysts such as MnOx for Li-O2 batteries.
自碳纳米管被发现以来其优异的性能使其具有在诸多领域应用,而如何更好地分散其一直是研究的一个重点。目前关于分散的机理和性能的研究存在不足,针对该问题本研究选择了十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(SDBS)、十六烷基三甲基溴化铵(CTAB)三种不同离子型表面活性剂在不同浓度下与三种直径的碳纳米管制备为分散体系,利用UV-vis光谱、FT-IR光谱,Raman光谱,TEM、Zeta电位分析对其分散性能和分散机理进行分析,结果表明十二烷基苯磺酸钠具有的苯环于碳纳米管产生了π-π键作用使其分散性能优于其他两种表面活性剂,并通过不同表面活性剂浓度下分子链长度的对比解释表面活性剂在不同浓度下与碳纳米管的作用机理。Since the discovery of carbon nanotubes, their excellent properties have made them applicable in many fields, and how to better disperse them has always been a research focus. At present, there is a lack of research on the mechanism and performance of dispersion. To address this issue, this study selected three different ionic surfactants, sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and hexadecyltrimethylammonium bromide (CTAB), to prepare dispersion systems with three different diameters of carbon nanotubes at different concentrations. UV-vis spectroscopy, FT-IR spectroscopy, Raman spectroscopy, and TEM were used to analyze their dispersion performance and mechanism. The results indicate that the benzene ring in sodium dodecylbenzenesulfonate forms π-π bonding with carbon nanotubes, leading to superior dispersion performance compared to the other two surfactants. Furthermore, by comparing the lengths of molecular chains at different surfactant concentrations, the mechanism of interaction between surfactants and carbon nanotubes at varying concentrations is explained.
锂离子电池是目前应用最广的二次电池,但锂电池的低温充放电性能还不能满足市场化应用。本文利用形状记忆温控开关,设计能够主动闭合、断开的锂离子电池低温加热管理系统;在此基础上,本文搭建了既能给手机电池充电又能给手机电池加热的多功能充电宝。本文设计搭建的多功能充电宝主要由壳体、电池组件、形状记忆合金上触头、形状记忆合金下触头、底座、低温加热接口、USB输出接口、充电接口、开关按钮、加热片等组成,可在低温环境下通过开关按钮控制将手机数据线接入充电宝USB输出接口完成充电功能。低温充放电性能测试表明,低温加热环境下锂电池循环寿命为1000小时,是未加热条件下锂电池的10倍。本文设计搭建的多功能充电宝将为深海、极地以及高纬度极寒地区锂电池的商业化应用提供很好的借鉴。Lithium-ion batteries are the most widely used secondary batteries, but the low-temperature charging and discharging performance of lithium batteries cannot meet the market application requirements. In this paper, a lithium-ion battery low-temperature heating management system with an active closing and opening function is designed using shape memory alloy temperature control switches. Based on this, a multi-functional portable charger that can both charge and heat the mobile phone battery is built. The multi-functional portable charger designed and built in this paper mainly consists of a shell, a battery component, a shape memory alloy upper contact, a shape memory alloy lower contact, a base, a low-temperature heating interface, a USB output interface, a charging interface, a switch button, a heating sheet, etc. It can complete the charging function by connecting the mobile phone data line to the USB output interface of the portable charger through the switch button in the low-temperature environment. The low-temperature charging and discharging performance test shows that
