超级电容器氧化物电极材料的研究进展

综述了近年来超级电容器氧化物电极材料的研究进展和现状 ,指出了电化学电容器 ,不论是双电容器 ,还是以准电容为基础的超级电容器 ,要想满足市场的需求 ,对电极活性材料的选择是十分重要的。并探讨了其发展方向和研究重点。

超级电容器氧化物电极材料的研究进展

对不同电极材料的储能机理和性能特点进行了简要的阐述,并详细综述了氧化钌、氧化镍、氧化钴等超级电容器电极材料的研究进展和现状,并探讨了其发展方向和研究重点.

超级电容器氧化物电极材料研究进展

介绍了超级电容器氧化物电极的储能原理和特点,综述了近年来超级电容器氧化物电极材料的研究进展和现状,并探讨了其发展方向和研究重点.

赝电容型超级电容器电极材料研究进展

超级电容器作为一种新型环境友好型储能元件,具有传统电容器及化学电源无法比拟的优点,目前已在众多领域受到广泛关注。概述了基于法拉第反应储能原理的超级电容器电极材料包括金属氧化物材料及导电聚合物等材料的最新研究进展,在此基础上提出了纳米多元金属复合电极和以导电聚合物/纳米多孔碳为基底的柔性纳米复合电极为超级电容器电极材料的发展方向。

Effects of synthesis conditions on layered Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_2 positive-electrode via hydroxide co-precipitation method for lithium-ion batteries

Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.

苏州枫港钛材设备制造有限公司

苏州枫港钛材设备制造有限公司地处苏州高新技术产业开发区，是一家致力于生产和研发稀有金属化工设备和不溶性阳极材料的民营高新技术企业，公司的主要产品有稀有金属（钛、钽、铌）化工设备和金属氧化物电极材料，公司拥有强大的技术力量和较先进的工艺装备，具有较高的研究水平和开发能力．

Enhancement of lithium storage capacity and rate performance of Se-modified MnO/Mn3O4 hybrid anode material via pseudocapacitive behavior

To improve rate and cycling performance of manganese oxide anode material,a precipitation method was combined with thermal annealing to prepare the Mn O/Mn3O4/Se Ox(x=0,2)hybrid anode by controlling the reaction temperature of Mn2O3 and Se powders.At 3 A/g,the synthesized Mn O/Mn3O4/Se Ox anode delivers a discharge capacity of 1007 m A·h/g after 560 cycles.A cyclic voltammetry quantitative analysis reveals that 89.5%pseudocapacitive contribution is gained at a scanning rate of 2.0 m V/s,and the test results show that there is a significant synergistic effect between Mn O and Mn3O4 phases.

La_(0.75)Sr_(0.25)Cr_(0.5)Mn_(0.5)O_(3)-δ−Ce_(0.8)Gd_(0.2)O_(1.9) composite electrodes as anodes in LaGaO_(3)-based direct carbon solid oxide fuel cells

Direct carbon solid oxide fuel cells(DC-SOFCs)are promising,green,and efficient power-generating devices that are fueled by solid carbons and comprise all-solid-state structures.Developing suitable anode materials for DC-SOFCs is a substantial scientific challenge.Herein we investigated the use of La_(0.75)Sr_(0.25)Cr_(0.5)Mn_(0.5)O_(3)-δ−Ce_(0.8)Gd_(0.2)O_(1.9)(LSCM−GDC)composite electrodes as anodes for La_(0.9)Sr_(0.1)Ga_(0.8)Mg_(0.2)O_(3)-δelectrolyte-based DC-SOFCs,with Camellia oleifera shell char as the carbon fuel.The LSCM−GDC-anode DC-SOFC delivered a maximum power density of 221 mW/cm^(2) at 800℃ and it significantly improved to 425 mW/cm^(2) after Ni nanoparticles were introduced into the LSCM−GDC anode through wet impregnation.The microstructures of the prepared anodes were characterized,and the stability of the anode in a DC-SOFC and the influence of catalytic activity on open circuit voltage were studied.The above results indicate that LSCM–GDC anode is promising to be applied in DC-SOFCs.

Iron-induced 3D nanoporous iron-cobalt oxyhydroxide on carbon cloth as a highly efficient electrode for oxygen evolution reaction

The development of highly efficient and cost-effective electrode materials for catalyzing the oxygen evolution reaction(OER)is crucial for water splitting technology.The increase in the number of active sites by tuning the morphology and structure and the enhancement of the reactivity of active sites by the incorporation of other components are the two main strategies for the enhancement of their catalytic performance.In this study,by combining these two strategies,a unique three-dimensional nanoporous Fe-Co oxyhydroxide layer coated on the carbon cloth(3D-FeCoOOH/CC)was successfully synthesized by in situ electro-oxidation methods,and directly used as a working electrode.The electrode,3D-FeCoOOH/CC,was obtained by the Fe doping process in(NH4)2Fe(SO4)2,followed by continuous in situ electro-oxidization in alkaline medium of“micro go chess piece”arrays on the carbon cloth(MCPAs/CC).Micro characterizations illustrated that the go pieces of MCPAs/CC were completely converted into a thin conformal coating on the carbon cloth fibers.The electrochemical test results showed that the as-synthesized 3D-FeCoOOH/CC exhibited enhanced activity for OER with a low overpotential of 259 mV,at a current density of 10 mA cm^–2,and a small Tafel slope of 34.9 mV dec^–1,as well as superior stability in 1.0 mol L^–1 KOH solution.The extensive analysis revealed that the improved electrochemical surface area,conductivity,Fe-Co bimetallic composition,and the unique 3D porous structure together contributed to the enhanced OER activity of 3D-FeCoOOH/CC.Furthermore,the synthetic strategy applied in this study could be extended to fabricate a series of Co-based electrode materials with the dopant of other transition elements.

Doping effects on the electro-degradation of phenol on doped titanium suboxide anodes

Titanium suboxide is an excellent electrode material for many oxidization reactions.In this article,the electrodes of pure Ti_4O_7,doped Ti_4O_7and the mixed-crystal of Ti_4O_7and Ti_5O_9were prepared to evaluate their activities and doping effects in the electro-degradation of phenol.It was revealed by the HPLC analysis results that the degradation intermediates and routes were significantly affected by the doping element.On the pure Ti_4O_7anode,a series of classic intermediates were obtained from benzoquinone and hydroquinone to various carboxylic acids.These intermediates were degraded gradually to the final organic intermediate of oxalate in all experiments.At last,oxalate was oxidized to CO_2and H_2O.Distinctively,the Y-doped Ti_4O_7 anode directly broke phenol toα-ketoglutaric acid without the intermediates of benzoquinone and hydroquinone.The strong oxidization ability of the Y-doped Ti_4O_7 anode might be responsible for the highest COD removal ratio.In contrast,the Ga-doped Ti_4O_7 anode showed the worst degradation activity in this article.Three intermediates of benzoquinone,hydroquinone and maleic acid were found during the degradation.Benefiting from the weak ability,oxalate was efficiently accumulated with a very high yield of 74.6%.The results demonstrated promising applications from electrochemical preparation to wastewater degradation by adjusting the doping reagent of Ti_4O_7 electrodes.

Ln_2MO_4 cathode materials for solid oxide fuel cells

One of the major challenges to develop "intermediate temperature" solid oxide fuel cells is finding a novel cathode material, which can meet the following requirements: (1) high electronic conductivity; (2) chemical compatibility with the electrolyte; (3) a matched thermal expansion coefficient (TEC); (4) stability in a wide range of oxygen partial pressure; and (5) high catalytic activity for the oxygen reduction reaction (ORR). In this short review, a survey of these requirements for K2NiF4-type material with the formula Ln2MO4, Ln = La, Pr, Nd, Sm; M = Ni, Cu, Fe, Co, Mn, is presented. The composition-dependent TEC, electrical conductivity and oxygen transport property are considered. The Ln2MO4 materials exhibit improved chemical stability and compatibility with most of the traditional electrolytes. The complete fuel cells integrated with Ln2MO4 materials as cathodes show promising results. Furthermore, these materials are considered as cathodes of protonic ceramic fuel cell (PCFC), and/or anodes of high temperature steam electrolysis (HTSE). First results show excellent performances. The versatility of these Ln2MO4 materials is explained on the basis of structural features and the ability to accommodate oxygen non-stoichiometry.

Nanostructuring the electronic conducting La_(0.8)Sr_(0.2)MnO_(3-δ) cathode for high-performance in proton-conducting solid oxide fuel cells below 600℃

Proton-conducting oxides offer a promising electrolyte solution for intermediate temperature solid oxide fuel cells（SOFCs） due to their high conductivity and low activation energy. However, the lower operation temperature leads to a reduced cathode activity and thus a poorer fuel cell performance. La_（0.8）Sr_（0.2）MnO_（3-δ）（LSM） is the classical cathode material for high-temperature SOFCs, which lack features as a proper SOFC cathode material at intermediate temperatures.Despite this, we here successfully couple nanostructured LSM cathode with proton-conducting electrolytes to operate below600℃ with desirable SOFC performance. Inkjet printing allows depositing nanostructured particles of LSM on Y-doped Ba ZrO_3（BZY） backbones as cathodes for proton-conducting SOFCs, which provides one of the highest power output for the BZY-based fuel cells below 600 ℃. This somehow changes the common knowledge that LSM can be applied as a SOFC cathode materials only at high temperatures（above 700 ℃）.

Facile electrodeposition of 3D concentration-gradient Ni-Co hydroxide nanostructures on nickel foam as high performance electrodes for asymmetric supercapacitors

Novel three-dimensional （3D） concentration-gradient Ni-Co hydroxide nanostructures （3DCGNC） have been directly grown on nickel foam by a facile stepwise electrochemical deposition method and intensively investigated as binder- and conductor-free electrode for supercapacitors. Based on a three- electrode electrochemical characterization technique, the obtained 3DCGNC electrodes demonstrated a high specific capacitance of 1,760 F·g^-1 and a remarkable rate capability whereby more than 62.5% capacitance was retained when the current density was raised from 1 to 100 A·g^-1. More importantly, asymmetric supercapacitors were assembled by using the obtained 3DCGNC as the cathode and Ketjenblack as a conventional activated carbon anode. The fabricated asymmetric supercapacitors exhibited very promising electrochemical performances with an excellent combination of high energy density of 103.0 Wh·kg^-1 at a power density of 3.0 kW·kg^-1, and excellent rate capability-energy densities of about 70.4 and 26.0 Wh·kg^-1 were achieved when the average power densities were increased to 26.2 and 133.4 kW·kg^-1, respectively. Moreover, an extremely stable cycling life with only 2.7% capacitance loss after 20,000 cycles at a current density of 5 A·g^-1 was achieved, which compares very well with the traditional doublelayer supercapacitors.

Hierarchically nanostructured transition metal oxides for supercapacitors

Highly efficient, clean, and sustainable electrochemical energy storage technologies have been investigated extensively to counter the shortage of fossil fuels and increasingly prominent environmental problems. Supercapacitors（SCs） have received wide attention as critical devices for electrochemical energy storage because of their rapid charging-discharging capability and long life cycle. Various transition metal oxides（TMOs）, such as MnO_2, NiO, Co_3O_4,and CuO, have been extensively studied as electrode materials for SCs. Compared with carbon and conducting polymers,TMO materials can achieve higher specific capacitance. For further improvement of electrochemical performance, hierarchically nano structured TMO materials have become a hot research area for electrode materials in SCs. The hierarchical nanostructure can not only offer abundant accessible electroactive sites for redox reactions but also shorten the ion diffusion pathway. In this review, we provide an overall summary and evaluation of the recent progress of hierarchically nano structured TMOs for SCs, including synthesis methods, compositions, structures, and electrochemical performances. Both single-phase TMOs and the composites based on TMOs are summarized. Furthermore, we also prospect the developing foreground of this field. In this view, the important directions mainly include： the nanocomposites of TMOs materials with conductive materials; the cobalt-based materials and the nickel-based materials; the improvement of the volume energy density, the asymmetric SCs, and the flexible all-solid-state SCs.

Understanding the defect chemistry of oxide nanoparticles for creating new functionalities:A critical review

This work presents a critical review on the studies of defect chemistry of oxide nanoparticles for creating new functionalities pertinent to energy applications including dilute-magnetic semiconductors,giant-dielectrics,or white light generation.Emphasis is placed on the relationships between the internal structure and defective surfaces of oxide nanoparticles and their synergy in tailoring the materials properties.This review is arranged in a sequence:(1) structural fundamentals of bulk oxides,using TiO2 as a model simple oxide to highlight the importance of polymorphs in tuning the electronic structures;(2) structural features of simple oxide nanoparticles distinct from the bulk,which show that nanoparticles can be considered as a special solid under the compression as originated from the surface defect dipole-dipole interactions;and(3) new functions achieved through extending the defect chemistry concept to the assembled architectures or multi-component oxide nanoparticles,in which defect surfaces enable the localized electrons or intermediate levels to produce giant dielectric performance or tunable light generation.It is concluded that understandings of defect chemistry provide diverse possibilities to manipulate electrons in oxide nanoparticles for functionalities in energy-relevant applications.

Recent progress on Ge oxide anode materials for lithium-ion batteries

1 Introduction As environmental pollution continues to worsen,governments are increasing their efforts to develop green transport vehicles,such as electric vehicles and hybrid cars.

A durable P2-type layered oxide cathode with superior low-temperature performance for sodium-ion batteries

To power large-scale energy storage systems,sodium-ion batteries(SIBs)must have not only high-energy density but also high performance under a low-temperature(LT)environment.P2-type manganese oxides with high specific capacity are promising cathode candidates for SIBs,but their LT applications are limitedly explored.We proposed a P2-type Na_(0.67)Ni_(0.1)Co_(0.1)Mn_(0.8)O_(2) material with outstanding LT performance prepared through reasonable structure modulation.The material offers an excellent Na^(+) diffusion coefficient(approximately 10^(−9)-10^(−7.5) cm^(2) s^(−1))at−20℃,a superior LT discharge capacity of 147.4 mA h g^(−1) in the Na half-cell system,and outstanding LT full cell performance(energy density of 358.3 W h kg^(−1)).Various characterisations and density function theory calculations results show that the solid solution reaction and pseudocapacitive feature promote the diffusion and desolvation of Na+from the bulk electrode to interface,finally achieving superior electrochemical performance at LT.

First principles study on methane reforming over Ni/TiO2（110） surface in solid oxide fuel cells under dry and wet atmospheres

Understanding the carbon-tolerant mechanisms from a microscopic view is of special importance to develop proper anodes for solid oxide fuel cells.In this work,we employed density-functional theory calculations to study the CH4 reaction mechanism over a Ni/TiO2 nanostructure,which experimentally demonstrated good carbon tolerance.Six potential pathways for methane reforming reactions were studied over the Ni/TiO2(110)surface under both dry and wet atmospheres,and the main concerns were focused on the impact of TiO2 and Ni/TiO2 interface on CO/H2 formation.Our calculations suggest that the reaction between carbon and the interfacial lattice oxygen to form CO*is the dominant pathway for CH4 reforming under both dry and wet atmospheres,and intervention of steam directly to oxidize C*with its dissociated OH*group is less favorable in energy than that to wipe off oxygen vacancy to get ready for next C*oxidation.In all investigated paths,desorption of CO*is one of the most difficult steps.Fortunately,CO*desorption can be greatly promoted by the large heat released from the previous CO*formation process under wet atmosphere.H2O adsorption and dissociation over the TiO2 surface are found to be much easier than those over Ni,yttria stabilized zirconia(YSZ)and CeO2,which should be the key reason for the greatly depressed carbon deposition over Ni-TiO2 particles than traditional YSZ-Ni and CeO2-Ni anode.Our study presents the detailed CO*formation mechanism in CH4 reforming process over the Ni/TiO2 surface,which will benefit future research for exploring new carbon-tolerant solid oxide fuel cell anodes.

Carbon-emcoating architecture boosts lithium storage of Nb_(2)O_(5)

Intercalation transition metal oxides (ITMO)have attracted great attention as lithium-ion battery negative electrodes due to high operation safety,high capacity and rapid ion intercalation.However,the intrinsic low electron conductivity plagues the lifetime and cell performance of the ITMO negative electrode.Here we design a new carbon-emcoating architecture through single CO_(2)activation treatment as demonstrated by the Nb_(2)O_(5)/C nanohybrid.Triple structure engineering of the carbon-emcoating Nb_(2)O_(5)/C nanohybrid is achieved in terms of porosity,composition,and crystallographic phase.The carbon-embedding Nb_(2)O_(5)/C nanohybrids show superior cycling and rate performance compared with the conventional carbon coating,with reversible capacity of 387 m A h g(-1)at 0.2 C and 92%of capacity retained after 500cycles at 1 C.Differential electrochemical mass spectrometry(DEMS) indicates that the carbon emcoated Nb_(2)O_(5)nanohybrids present less gas evolution than commercial lithium titanate oxide during cycling.The unique carbon-emcoating technique can be universally applied to other ITMO negative electrodes to achieve high electrochemical performance.

Metal Oxide/graphene composite anode materials for lithium-ion batteries

Metal oxides, such as SnO2, Fe2O3, Fe3O4, CoO, Co3O4, NiO, CuO, Cu2O, MnO, Mn3O4, MnO2. etc. , are promising anode materi- als for lithium-ion batteries （LIBs） due to their high capacity and safety characteristics. However, the commercial utility of metal oxide anodes has been hindered to date by their poor cycling per- formance. Recent study shows that metal oxide/ graphene composites show fascinating cycling per- formance as anode materials for lABs. In this re- view, we summarize the state of research on prepa- ration of metal oxide/graphene composites and their I.i storage performance. The prospects and future challenges of metal oxide/graphene compos- ites anode materials for lABs are also discussed.