糖蜜酒精废液OD值测定条件的确定

糖蜜酒精废液光密度的测定没有统一的方法,通过正交试验和单因素试验,对糖蜜酒精废液的光密度(OD)值的测定条件进行了研究。结果表明在波长为400nm和自然pH值的测定条件下,OD值最大,稀释度为20倍时光密度值落在最佳读数范围内。     

Advanced Sn/C composite anodes for lithium ion batteries

Metallic tin was deposited in fine particulate form on the surface of carbonaceous mesophase spherules (CMS) and in the pores of porous carbon by the decomposition and reduction of tin(II) 2-ethylhexanoate at 450 °C. The Sn/C composite powders obtained were used as anode materials for lithium ion cells. Electrochemical cycling tests of coin cells show that the dispersion of tin into the carbonaceous materials enhances the reversible capacity of the electrodes. The capacity retention at the 50th cycle is 91 % for Sn/CMS composite containing 22% tin, against 428 mAh g^–1 at the first cycle. With further increase in tin content, the capacity fade upon cycling is more rapid.     

废旧锂电池中有价金属回收及三元正极材料的再制备

探讨了磷酸体系下不同因素对废旧锂电池正极材料中有价金属浸出效率的影响，结果表明：在浸出时间60min，反应温度60℃，磷酸浓度2mol/L，液固比20mL/g，还原剂(H₂O₂)体积分数为4%时，可得最佳浸出效果，Co、Li、Mn、Ni浸出效率分别可达96.3%、100%、98.8%和99.5%；浸出液添加相应比例金属离子，采用草酸共沉淀法制备前体材料(Ni_1/3Co_1/3Mn_1/3)C₂O₄，并得到相应再生磷酸溶液。再生磷酸进行循环浸出实验，实验研究结果表明：循环浸出5次之后Li的浸出率仍可保持在90.1%，而Co、Mn和Ni的浸出率在75.0%以上。前体添加锂源Li₂CO₃煅烧合成Li(Ni_1/3Co_1/3Mn_1/3)O₂材料，考察了不同温度对Li(Ni_1/3Co_1/3Mn_1/3)O₂材料合成的影响，结果显示，当合成温度为800℃时，得到的材料性能最优良，初次放电容量可达136.4mA·h/g。在0.2C下经过50圈循环后容量保持率为97.2%。     

Electrochemical investigation of LiNi0.5Mn1.5O4 thin film intercalation electrodes

This work provides kinetic and transport parameters of Li-ion during its extraction/insertion into thin film LiNi_0.5Mn_1.5O₄ free of binder and conductive additive. Thin films of LiNi_0.5Mn_1.5O₄ (0.2 μm thick) were prepared on electronically conductive gold substrate utilizing the electrostatic spray deposition technique. High purity LiNi_0.5Mn_1.5O₄ thin film electrodes were observed with cyclic voltammetry, to exhibit very sharp peaks, high reversibility, and absence of the 4 V signal related to the Mn³⁺/Mn⁴⁺ redox couple. The electrode subjected to 100 CV cycles of charge/discharge delivered a capacity of 155 mAh g⁻¹ on the first cycle and sustained a good cycling behavior while retaining 91% of the initial capacity after 50 cycles. Kinetics and mass-transport of Li-ion extraction at LiNi_0.5Mn_1.5O₄ thin film electrode were investigated by means of electrochemical impedance spectroscopy. The apparent chemical diffusion coefficient (D_app) value determined from EIS measurements changed depending on the electrode potential in the range of 10⁻¹⁰-10⁻¹² cm² s⁻¹. The D_app profile shows two minimums at the potential values close to the peak potentials of the corresponding cyclic voltammogram.     

锌溴液流电池安全性研究

针对锌溴液流电池电解液中溴易挥发,充电过充时以及充电过程中温度过高易造成安全性隐患,通过对溴络合剂,电氧化聚合电解液添加剂,电压敏感隔膜,温度敏感电极等,这些影响因素进行实验分析,结果表明溴络合剂采用四丁基溴化铵,电氧化聚合电解液添加剂采用4-溴苄基异氰酸酯,电压敏感隔膜采用聚对苯和聚二苯胺复合膜,温度敏感电极采用环氧树脂-炭黑复合物的PTC材料,就能很好的控制锌溴液流电池的安全性。     

锂离子电池正极材料的现状与发展

介绍了锂离子正极材料氧化钴锂、氧化镍锂、氧化锰锂、磷酸铁锂等研究开发和现状,对其特性进行了较为全面的总结。     

Ultrasonic spray pyrolysis of nano crystalline spinel LiMn2O4 showing good cycling performance in the 3 V range

Spherical lithium manganese oxide spinel was synthesized by an ultrasonic spray pyrolysis method, and has been characterized using X-ray diffraction, scanning electron microscopy, transimission electron microscopy and electrochemical cycling at 3 V regions. The LiMn₂O₄ powders were composed of about 10 nm-sized primary particles. The delivered discharge capacity of the synthesized nano-material was 125 mAh g⁻¹ between 2.4 and 3.5 V and its retention was about 96% upon 50 cycling. From the high resolution transmission electron microscopic study, it was found that structural transition of the parent material did not occur even after the 50th electrochemical cycling on the 3 V region. It seems that the reversible structural change is possible for nanocrystalline LiMn₂O₄ as observed by the X-ray diffraction and transition electron microscopic observations.     

飞机碱性电瓶充放电参数测量仪的设计与研究

电瓶是民航飞机可靠供电的最后保证。飞机制造厂家提高了对电瓶的性能和容量检测要求,传统的电瓶充放电装置已经无法满足新的要求。利用单片机技术研制的飞机电瓶参数测试仪,实现了对电瓶各种参数的实时侧量和分析,为飞机电瓶维护和检测提供依据。     

Electrochemical characteristics of phase-separated polymer electrolyte based on poly(vinylidene fluoride-co-hexafluoropropane) and ethylene carbonate

A polymer electrolyte based on microporous poly(vinylidene fluoride-co-hexafluoropropane) (PVdF-HFP) film was studied for use in lithium ion batteries. The microporous PVdF-HFP (Kynar 2801) matrix was prepared from a cast of homogeneous mixture of PVdF-HFP and solvents such as ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). After evaporation of DMC and EMC, a sold film of the PVdF-HFP and the EC mixture was obtained. EC-rich phase started its formation in the PVdF-HFP/EC film at EC content of about 60 wt.% based on the total weight of PVdF-HFP and EC. The formation of the new phase resulted in the abrupt increase of the porosity of the PVdF-HFP matrix from 32 to 62%. The ionic conductivity of the film soaked in 1 M LiPF₆-EC/DMC=1/1 was significantly increased from order of 10⁻⁴ S/cm to order of 10⁻³ S/cm at the EC content of 60 wt.%. Thermal and spectroscopic investigations showed that most of the EC interact with PVdF-HFP with the EC content being below 60 wt.%. MCMB/polymer electrolyte/LiCoO₂ cells employing the microporous PVdF-HFP polymer film showed stable charging/discharging characteristics at 1C rate and good rate capability.