金属有机聚合物衍生Co3O4的制备及其储锂性能

以偏苯三甲酸和Co(NO3)2?6H2O为原料,通过溶剂热法合成了一种钴基金属有机聚合物(Co-MOP).然后对Co-MOP进行高温(500、600、700℃)煅烧得到Co-MOP衍生材料(Co-MOP-500、Co-MOP-600、Co-MOP-700).采用XRD、SEM、TEM、XPS、BET对Co-MOP及其衍生材料进行了结构和形貌表征.将Co-MOP衍生材料用作锂离子电池负极材料,并进行了电化学性能测试.结果表明,Co-MOP衍生材料均为Co3O4,Co-MOP-600形成了较为稳定结构的多孔球,较好地保持了Co-MOP的形貌,其比表面积为19.9 m2/g.Co-MOP-600具有优异的电化学性能.在100 mA/g电流密度下,Co-MOP-600电极的首圈放电比容量达到1818.5 mA·h/g,循环100圈后其比容量还能维持在1308.5 mA·h/g,Co-MOP-600稳定的多孔球形结构为锂离子的储存提供了更多的活性位点和运输通道.     

金属有机聚合物基负极材料的制备及其储锂性能Q

为了寻求优异电化学性能的新型金属有机聚合物基负极材料，以偏苯三甲酸作为有机配体和六水硝酸钴进行配位，通过水热法合成了一种新型的钴基金属有机聚合物（Co-MOP）。在空气气氛下，对Co-MOP分别以500 ℃、600 ℃、700 ℃高温煅烧获得相应的Co-MOP-500、Co-MOP-600、Co-MOP-700衍生材料。Co-MOP衍生材料用作锂离子电池负极材料进行了研究。电化学测试结果显示Co-MOP-600展现出了优异的电化学性能。在100 mA/g的电流密度下，Co-MOP-600电极的首圈放电比容量达到1818.5 mAh/g，循环100圈后比容量还能维持1308.5 mAh/g。     

溶胶-凝胶自蔓延法制备纳米Co3O4的研究

采用溶胶-凝胶自蔓延燃烧法制备锂离子电池纳米Co3O4负极材料,利用XRD、SEM和充放电测试等手段表征了不同的原料比和热处理温度对材料的结构、颗粒形貌和电化学性能的影响。实验表明:硝酸钴和柠檬酸摩尔比为1∶2,400℃空气气氛下热处理制备的Co3O4材料表现出良好的电化学性能。首次可逆容量为1121.4 m Ahg-1,循环30次后可逆容量仍能高达865.3 m Ahg-1,容量保持率约为77.2%。     

微波辅助金属有机骨架材料制备无定形Co3O4花球及其电化学性能

以六水合硝酸钴(Co(NO3)2?6H2O)、苯甲酰丙酮（C10H10O2）为原料, 利用微波法合成了前体。前体在500℃空气条件下锻烧得到无定形Co3O4花球。通过 XRD、 SEM、TEM对目标产物进行了表征 , 研究了无定形Co3O4花球的微观结构、表面形貌。电化学测试结果表明,无定形Co3O4花球负极材料 在100mA/g的电流密度下,首次充电比容量达到826mAh/g;循环100圈后,容量保持率为89.2％,具有高的比容量、良好的循环性能和广泛的应用前景。     

Li4Ti5O12/Fe3O4复合材料的制备及其电化学性能

以醋酸锂和钛酸四正丁酯为原料,制备了纯相Li_4Ti_5O_(12),再用简单的水热法合成Li_4Ti_5O_(12)/Fe_3O_4复合材料作为锂离子电池的负极材料,通过XRD、SEM以及电池测试系统对纯相Li_4Ti_5O_(12)和Li_4Ti_5O_(12)/Fe_3O_4复合材料进行了结构、形貌及电化学性能测试。结果表明,制得的复合物具有较好的球形结构且粒径较小(200～300 nm),综合电化学性能较好。由于复合的Fe_3O_4有较高的理论容量,该Li_4Ti_5O_(12)/Fe_3O_4复合材料表现出比纯相Li_4Ti_5O_(12)大的容量,在1.0 C下循环100圈后,Li_4Ti_5O_(12)/Fe_3O_4的放电比容量仍能达到470.2 m A·h/g,同时也表现出比纯相Li_4Ti_5O_(12)更优的倍率性能。     

一步法制备Co3O4及其电化学性能研究

以六水合硝酸钴为钴源、二甲基咪唑为有机配体,通过室温共沉淀法合成前驱体模板ZIF-67,而后再高温煅烧形成目标产物Co₃O₄材料。利用X-射线衍射与扫描电镜对目标产物进行表征,而后选用蓝电电池测试系统测试其倍率与循环性能。测试表明,在100mA/g电流密度条件下,Co₃O₄电极的首次充电容量和放电容量分别可有2069.2mAh/g和2928.3mAh/g,首次库伦效率有70.66%,循环使用寿命长,但容量维持率低,经100圈测试后容量保持率仅有35%;而在倍率测试中发现即使经过50次充放电,电流密度从2000mA/g回到100mA/g时,Co₃O₄电极的放电容量依然可以保持有1482mA/g,并且表现出良好的循环稳定性,说明Co₃O₄即使经过高倍率充放电,其结构依然可以保持稳定,具有较为不错的倍率性能。     

微波辅助制备不规则Co_3O_4花球及其电化学性能

以六水合硝酸钴、苯甲酰丙酮为原料,利用微波法合成了Co_3O_4花球前驱体,并在500℃空气条件下锻烧得到不规则Co_3O_4花球。通过XRD、SEM、TEM对不规则Co_3O_4花球的微观结构和表面形貌进行了表征。电化学测试结果表明,不规则Co_3O_4花球负极材料在0.1 A/g的电流密度下,首次充电比容量达到816 m A·h/g,循环100圈后,比容量保持率为89.2%;倍率性能测试结果表明,电流密度从0.1 A/g增加到1 A/g时,比容量有一定的衰减,但电流密度恢复到0.1 A/g时,比容量几乎恢复到原来的水平;阻抗测试结果表明,不规则Co_3O_4花球负极材料循环前内阻为335Ω,50圈循环后内阻减小到240Ω。制备的不规则Co_3O_4花球具有较高的充电比容量、良好的循环性能和倍率性能。     

TiNb2O7@N-C纳米复合材料的制备及储锂性能研究

以1-乙基-3-甲基咪唑二氰铵为氮碳源,利用溶胶-凝胶法一步制得TiNb2O7@N-C纳米复合材料.采用X-射线衍射仪、扫描和透射电镜、恒流充放电等手段进行表征分析.TiNb2O7@N-C纳米复合材料的颗粒尺寸约50 nm,并且颗粒表面均匀包覆着厚度约为2 nmn的N掺杂碳层.作为锂离子电池负极,TiNb2O7@N-C...     

环氧树脂辅助制备LiNi1/3Co1/3Mn1/3O2及其储锂性能

采用环氧树脂来均匀分散Li~+,Co~(2+),Mn~(2+)和Ni~(2+),并通过环氧树脂低温固化来维持离子均匀分散,续以空气中充分煅烧制备LiNi1/3Co_(1/3)Mn_(1/3)O2材料。电化学研究显示,850℃下制得的材料具有更好的充放电性能,0.2℃倍率下的首次充放电容量分别达到186.4和135.1mAh·g~(-1)。     

Co3O4 microtubules derived from a biotemplated method for improved lithium storage performance

A simple and effective biotemplated method is applied to fabricate porous microtubular cobalt oxide by infiltration of cotton fiber with a cobalt nitrate solution, followed by annealing at 500 °C in air. The as-obtained Co₃O₄ have been characterized by: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), N₂ adsorption and desorption measurements, and thermal analysis (TG). According to these results, the as-prepared Co₃O₄ display a perfect tubular morphology and mesoporous features. The electrochemical performance of the as-obtained sample was studied for use as a lithium-ion battery anode material by cyclic voltammetry (CV), and charge-discharge and electrochemical impedance spectroscopy (ESI) measurements. Compared to bulk Co₃O₄ and previously reported nanostructured Co₃O₄ electrodes, mesoporous microtubular Co₃O₄ show an improved lithium storage properties, which can be attributed to their unique morphology, large specific surface area and mesoporous feature.     

纳米颗粒组装三维Co3O4微米花材料制备及储锂性能研究

通过软模板法(表面活性剂十六烷基三甲基溴化铵,CTAB)结合后续空气气氛热处理制备出纳米颗粒组装三维Co₃O₄微米花负极材料。研究中采用X射线衍射分析(XRD)、场发射扫描电子显微镜(FESEM)、循环伏安测试(CV)、恒流充放电测试以及交流阻抗测试(EIS)对合成样品进行表征分析。研究结果显示,Co₃O₄微米花材料独特的结构优势赋予其优良的电化学性能,在100 mA·g^-1电流密度下电极具备约920 mA·h·g^-1的循环可逆比容量;在500 mA·g^-1电流密度下循环200次后的循环可逆比容量为757 mA·h·g^-1,容量几乎无衰减。大电流循环性能测试显示,所制备电极即使在2 A·g^-1电流密度下依旧具有476 mA·h·g^-1的循环可逆比容量。简易、有效且低成本化的高性能微米花结构过渡金属氧化物负极材料制备工艺将大大加速转换型电极材料的实际有效应用。     

High lithium storage of Co3O4 enabled by integrating hollow and porous carbon scaffolds

The Co₃O₄, as a potential anode of lithium-ion batteries, has gained considerable attention because of high theoretical capacity. However, the Co₃O₄ is suffering from serious structure deterioration and rapid capacity fading due to its bulky volume change during cyclic charge/discharge process. Herein, to stabilize the lithium storage performance of the Co₃O₄ nanoparticles, a characteristic carbon scaffold (HPC) integrating hollow and porous structures has been fabricated by a well-designed method for the first time. The ultrafine Co₃O₄ nanoparticles are cleverly anchored on the HPC (HPC@Co₃O₄) and hence achieve significantly improved electrochemical properties including high capacity, improved reaction kinetics and outstanding cycle stability, showing high capacity of 1084.7 mAh g^-1 after 200 cycles at 200 mA g^-1 as well as 681.4 mAh g^-1 after 300 cycles at 1000 mA g^-1. The HPC@Co₃O₄ therefore shows good promising for application in advanced lithium-ion battery anodes. The results of the systematically material and electrochemical characterizations indicate that the synergistic effects of ultrafine Co₃O₄ nanoparticles and well-designed HPC scaffolds are responsible for the outstand performance of the HPC@Co₃O₄ anode. Moreover, this work can enrich the understanding and development of stable and high-performance metal oxide-based lithium-ion battery anodes for advanced lithium storage.     

Co3O4-Bi2O2CO3催化剂的制备及其光催化性能

以Bi(NO₃)₃·5H₂O、Co(CH₃COO)₂·4H₂O为原料,采用化学沉淀-水热法制备了Co₃O₄-Bi₂O₂CO₃异质结构复合半导体光催化剂,并通过X射线衍射仪（XRD）、扫描电镜（SEM）、X射线光电子能谱（XPS）、紫外可见漫反射光谱（DRS）、荧光光谱（PL）等手段对所合成的复合型催化剂进行了理化性能表征。研究结果表明：引入Co₃O₄没有改变Bi₂O₂CO₃物相结构,但促进了Bi₂O₂CO₃ 对可见光的吸收能力,提高了Bi₂O₂CO₃表面吸附氧物种的数量,抑制了光生载流子复合。复合光催化剂对罗丹明B（RhB）的光催化脱色实验显示引入Co₃O₄能够明显提高Bi₂O₂CO₃催化剂的光催化脱色能力。尤其是Co₃O₄引入量为0.6%的Co₃O₄-Bi₂O₂CO₃样品对罗丹明B染料的光催化脱色率可达到97%（模拟日光照射30min）。本文为复合型光催化剂制备提供了简单易行的技术路线,制备的新型半导体复合光催化剂Co₃O₄-Bi₂O₂CO₃在环境净化方面表现出了较好的应用前景。     

Graphene aerogel encapsulated Co3O4 microcubes derived from prussian blue analog as integrated anode with enhanced Li-ion storage properties

In lithium-ion batteries (LIB), cobalt oxide is considered an ideal anode material because of its theoretical specific capacity of up to 890 mAh g⁻¹, abundant resources, and low price. However, the volume expansion during the charging and discharging process and its lower conductivity have hindered its development. In this work, a metal-organic framework (MOF) was used as an initial template, encapsulated in graphene aerogels (GA) by hydrothermal and programmed temperature-controlled annealing and eventually formed into Co₃O₄ microcubes@GA composite. GA acts as a three-dimensional conductive network and mechanical skeleton, providing high electrical conductivity and structural stability to the composites. Moreover, the precursor's high porosity and stable structure are retained after annealing treatment. As an anode, the best long cycle life of Co₃O₄ microcubes@GA was achieved when the graphene oxide (GO) concentration was 3.0 mg ml⁻¹, reaching 1234.9 mAh g⁻¹ after 200 cycles at 1 A g⁻¹ with a coulomb efficiency (CE) of 98.97%.     

Co3O4负载纳米Au催化剂的制备

利用共沉淀法（CP）和沉积-沉淀法（DP）制备了Au／C0304催化剂,考察了制备条件及不同制备方法对金粒子大小的影响。结果表明,负载量为1wt％Au／Co3O4金粒子最小,分散度最好,而焙烧温度太高不利于金粒子的分散,另外,DP法制备的金粒子比CP法制备的要小。     

Porous rod-shaped Co3O4 derived from Co-MOF-74 as high-performance anode materials for lithium ion batteries

Porous rod-shaped Co₃O₄ has been successfully synthesized by one-step thermal annealing of the as-prepared Co-MOF-74 precursor and tested as anode materials for lithium ion batteries. The porous rod-shaped Co₃O₄ is found to be very attractive for lithium-ion batteries. It demonstrates a reversible capacity of 683 mAh/g after 80 cycles at 100 mA/g and an excellent rate performance with high average discharge specific capacities of 1231, 1026, 733 and 502 mAh/g at 50, 100, 200 and 400 mA/g, respectively. The excellent electrochemical performance should be due to the porous structural and composition characteristics.