锂离子电池正极材料层状LiNi1/2Mn1/2O2的制备与表征

用一种简单的共沉淀法制备出了层状LiNi1/2Mn1/2O2材料，并且用XRD、SEM、循环充放电、循环伏安(CV)和电化学阻抗谱(EIS)等方法对材料进行了表征测试。首先，用共沉淀法制备氢氧化镍和氢氧化锰的混合物：然后,对共沉淀溶液进行预氧化来制备前驱体；最后，用预氧化的前驱体合成了LiNi1/2Mn1/2O2材料。SEM 和XRD测试结果分别表明：LiNi1/2Mn1/2O2材料是粒径范围在100～200 nm之间的球形粒子，并且具有非常好的层状结构。循环充放电表明：在空气中900℃下合成时间为9 h的材料．在充放电截止电压为2.8～4.6 V的情况下，经过40次循环，材料的容量可以稳定地保持在140 mAh．g-1左右。循环伏安曲线表明：在锂的初始脱嵌和入嵌过程中存在不可逆相变。电化学阻抗谱测试表明LiNi1/2Mn1/2O2具有很好的锂离子扩散能力

synthesis and characterization of layered lini1/2mn1/2o2 as cathode material for lithium ion batteries

用一种简单的共沉淀法制备出了层状LiNi1/2Mn1/2O2材料,并且用XRD、SEM、循环充放电、循环伏安(CV)和电化学阻抗谱(EIS)等方法对材料进行了表征测试.首先,用共沉淀法制备氢氧化镍和氢氧化锰的混合物;然后,对共沉淀溶液进行预氧化来制备前驱体;最后,用预氧化的前驱体合成了LiNi1/2Mn1/2O2材料.SEM和XRD测试结果分别表明:LiNi1/2Mn1/2O2材料是粒径范围在100～200 nm之间的球形粒子,并且具有非常好的层状结构.循环充放电表明:在空气中900℃下合成时间为9 h的材料,在充放电截止电压为2.8～4.6 V的情况下,经过40次循环,材料的容量可以稳定地保持在140 mAh·g-1左右.循环伏安曲线表明:在锂的初始脱嵌和入嵌过程中存在不可逆相变.电化学阻抗谱测试表明LiNi1/2Mn1/2O2具有很好的锂离子扩散能力

A Study on Amorphous Ni P Alloy Brush Plating Solution

研究了电刷镀非晶态镍磷合金的镀液组成及工艺参数对镀层磷含量，沉积速度的影响，研究了刷镀溶液的综合工艺性能。在最佳工艺条件下获得的镍磷合金刷镀层，磷含量保持在（6~13）WT%，呈非晶态结构，沉积速度保持在60~90μM/H之间。Abstract The solution composition and the process for amorphous Ni P alloy brush plating of carbon steel were studied.The overall performances of the solution for brush plating were also investigated.The deposit obtained from optimum process contained 6%￣13% P(wt), and the microstructure was amorphous.The deposition rate is up to 60￣90 μm/h

Performance of Anaerobic Co-digestion of Maize Straw Silage and Cattle Manure

Ensiling is not only a conventional storage practice of forage grass,but also can be used for seasonal storage of biogas production materials. The aim of this paper is to evaluate the effects of different TS mixing ratios（ TMR） of cattle manure and ensil

Studies on the Cathodic Current Efficiency in the Electrodeposition Ni PSZ Gradient Coating

采用动电位扫描，电化学交流阻抗及扫描电子显微镜研究电沉积Ｎｉ－ＰＳＺ梯度镀层过程中阴极电流效率的变化规律及其机理．结果表明，Ｎｉ－ＰＳＺ复合镀层对氢的析出反应具有催化作用，在镀液中加入ＰＳＺ微粒后，能增大镍还原过电位，降低氢析出过电位，从而不断降低电沉积梯度镀层过程中的阴极电流效率．在电沉积Ｎｉ的过程中，有中间吸附相Ｎｉ＋ａｄｓ生成，ＰＳＺ微粒的加入能优先催化Ｈａｄｓ，加速氢气析出The cathodic current efficiency and the electrochemical behavior in electrodeposition Ni PSZ gradient coating were investigated by various electrochemical techniques and scanning electron microscope. The results showed that the Ni PSZ composite coatings can accelerate evolution of hydrogen with the increase of PSZ content. The overpotential of nickel reduction will be increased and that of hydrogen reaction will be reduced in the presence of PSZ particles in electrolyte. The effect of PSZ particles on nickel electrodeposition was preferentially to catalyze the formation of H ads . These all contributed to the lower current efficiency.作者联系地址：哈尔滨工业大学应用化学系Author's Address: Dept. of Chem., Harbin Inst. of Tech., Harbin 15000