Calendar and PHEV cycle life aging of high-energy, lithium-ion cells containing blended spinel and layered-oxide cathodes

One hundred seven commercially available, off-the-shelf, 1.2-Ah cells were tested for calendar life and CS cycle- and CD cycle-life using the new USABC PHEV Battery Test Manual. Here, the effects of temperature on calendar life, on CS cycle life, and on CD cycle life; the effects of SOC on calendar life and on CS cycle life; and the effects of rest time on CD cycle life were investigated. The results indicated that the test procedures caused performance decline in the cells in an expected manner, calendar < CS cycling < CD cycling. In some cases, the kinetic law changed with test type, from linear-with-time to about t². Additionally, temperature was found to stress the cells more than SOC, causing increased changes in performance with increasing temperature.     

城市再生水在电厂循环冷却水系统中的应用

介绍了城市再生水作为电厂循环冷却水补水水源的意 义及其水质要求,对其排污进行回用的处理工艺选择进行了 论证,并提供了详细的设计参数。结合北京京能热电股份有 限责任公司利用城市再生水作为循环冷却水补充水及其排污 回用处理工程投运情况进行了实例分析,得出了城市再生水 回用到电厂循环冷却水系统中是可行的,其排污水可利用“双 膜法”进行处理后回用。     

Slurry based multilayer environmental barrier coatings for silicon carbide and silicon nitride ceramics — II. Oxidation resistance

In part I of this study, the dip-coat processing of mullite/gadolinium silicate (Gd₂SiO₅) environmental barrier coatings (EBCs) applied on α-SiC and SN282™ Si₃N₄ through alcohol based and sol based slurries was presented. Here, the performance of selected EBCs by evaluating their oxidation resistances during thermal cycling in simulated combustion (90% H₂O-balance O₂) environment between 1350 °C and RT for up to 400 cycles is being reported. Oxidation of un-coated α-SiC was severe, leading to aligned and layered porous silica scale formation (~ 17 μm thick) on its surface with frequent scale spallation when exposed to 100 cycles. Mullite/Gd₂SiO₅/B₂O₃ (83.5/11.5/5 wt.%) EBCs remained adherent to α-SiC substrate with an underlying porous silica layer formed at substrate/coating interface, which was ~ 12 μm after 100 cycles, ~ 16 μm after 200 cycles, and ~ 25 μm after 400 cycles. In contrast, α-SiC substrate coated with mullite/Gd₂SiO₅ (88/12 wt.%) EBC had only limited oxidation of ~ 10 μm even after 1350 °C/400 cycles. The sol based mullite/Gd₂SiO₅ (88/12 wt.%) EBC on α-SiC substrate after 400 cycles was adherent, but showed more interfacial damages (~ 20 μm after 400 cycles) though it had increased coating density. However, the mullite/Gd₂SiO₅ (88/12 wt.%) EBC (alcohol based) delaminated from the SN282™ Si₃N₄ substrate after 1350 °C/100 cycles, because of the formation of interconnected interfacial voids and hairline cracks. Parabolic growth kinetics for the underlying silica was observed for both the alcohol and sol based coated samples.     

循环经济与热处理节能环保新技术探讨

遵循我国发展循环经济和走可持续发展的工业化道路的战略决策,针对国内热处理行业能耗高、污染重的现状,概述了热处理节能减排的内容、作用和意义。论述了新能源、先进燃烧技术、新钢种新材料、节能环保新工艺设备和修复热处理技术等的研发、技术特点和生产应用。     

硫酸盐干湿循环对再生骨料混凝土性能的影响

为了探讨再生骨料混凝土在硫酸盐作用下的耐久性能,选取再生粗骨料替代率为50％、100％的两组再生混凝土和普通骨料混凝土进行硫酸盐环境中的干湿循环试验.从侵蚀后混凝土表观形貌,质量、强度、超声波速经时变化规律分析混凝土的损伤特性.结果表明:再生骨料混凝土抗硫酸盐侵蚀能力小于普通骨料混凝土,且抗侵蚀能力随着再生骨料替代率的增加而降低.硫酸盐侵蚀后,混凝土质量、强度、超声波速经时变化曲线由上升段与下降段两部分组成.超声波法可以反映再生骨料混凝土侵蚀后的损伤特征.最后,建立了无量纲化超声波速与抗压强度之间的演化方程.     

基于PDCA循环的牛角山隧道光面爆破质量控制与技术改进

光面爆破质量直接关系到隧道施工的质量、安全及成本等,牛角山隧道凿岩爆破开挖施工过程中,采用PDCA循环质量管理方法,根据TM隧道断面测量系统采集的断面超欠挖数据,进行现场检查、讨论分析,找出影响光面爆破质量的主要因素,通过制定有针对性的改进措施并监督执行,较好地提高了光面爆破效果,一次循环进尺平均光面爆破合格率达到95%,炮眼残留率达到85%,不仅保证了隧道施工质量,而且降低了施工成本,加快了施工进度,获得了良好的质量效果和经济效益。     

VRLA电池的AGM隔板和氧传输(1)

VRLA电池实现了内部氧循环,电池可以密闭.充电时,正极产生的氧能通过具有良好传输性能的AGM隔板到达负极,与活性物质发生反应,被还原成水,这过程被称为氧再化合作用或密闭氧循环过程.这个反应过程,要求AGM隔板有良好的孔隙结构和高的孔隙率;AGM隔板的孔隙与负极活性物质的孔隙应当互相匹配;AGM隔板要有良好的耐酸性和弹性等.氧在AGM隔板中的传输速度不但与隔板的孔结构有关,还与隔板中电解液的饱和度有关.电解液的饱和度高时,氧的传输速度低;电解液的饱和度在60%左右时,氧的传输接近在气相中扩散的情况.在AGM隔板中添加适量憎水合成的玻璃纤维,可以增加隔板强度和电池的注酸量.     

乙醇发酵中酿酒酵母辅酶NAD+及NADH测定方法

乙醇发酵过程中酿酒酵母细胞辅酶NAD+和NADH质量分数及其比例反映了胞内的氧化还原状态和细胞代谢活性,具有重要的生理意义。作者主要研究了加热萃取、珠磨破碎、反复冻融破碎3种方法对乙醇发酵过程酿酒酵母细胞辅酶NAD+和NADH提取和测定的影响,提出基于珠磨破碎、辅以加酸或碱并加热的萃取模式,以及合适的酶循环反应体系,从而建立了高效的胞内NAD+和NADH检测方法。     

Application of SiO/C composite anode material for lithium -ion batteries

硅基材料因其较高的比容量而受到研究者广泛的关注。本文选取高比容量SiOx与NG复合材料作为锂离子电池负极材料,研究了不同SiO/C复合比例对全电池的能量密度和循环性能的影响。不同比例SiOx/C复合材料的首次容量和首次效率有明显差别。与石墨材料相比,SiOx/C复合材料的膨胀程度略有增加。随着SiOx比例的增加,全电池的能量密度先是上升然后下降,但其循环稳定性却有所降低。当SiOx比例在4%时,全电池能量密度提升1.2%,500周循环后容量保持率在80%以上,可以满足商业化锂离子电池的使用要求。     

The cycle life investigation for spinel LiNi0.5Mn1.5O4 full cells

分别以石墨和钛酸锂为负极活性物质,制备了尖晶石镍锰酸锂的32131型圆柱锂离子电池.石墨负极电池和钛酸锂负极电池容量分别为7.5 A·h和5.5 A·h,质量能量密度分别达到152 W·h/kg和81 W·h/kg.常温充放电循环测试结果表明,石墨和钛酸锂两种负极体系电池循环寿命将分别达到400次和1000次,这种循环寿命的差别主要体现在负极上,即正极材料中溶解的Mn在石墨负极表面沉积并持续催化SEI膜生成,减少了电池中可使用的活性Li⁺,进而导致电池寿命快速衰减;相比而言,钛酸锂负极表面不存在明显SEI,同时正极过量设计电池也使得钛酸锂体系电池的镍锰酸锂与电解液间的界面副反应低于石墨体系的负极过量设计电池.