2023 Vol. 8, No. 5

column
  Previous Issue | Next Issue 
Display Method:
Cover info & Content
[Front Cover]
[Back Cover]
[Download Content]
Viewpoint
The infinite separation principle
Suojiang Zhang
2023, 8(5): 1229-1231. doi: 10.1016/j.gee.2023.06.003
Abstract HTML PDF
Abstract:
In this paper, we propose “The Infinite Separation Principle”. This principle contains two implications: firstly, even exhausting all separation approaches, including chemical techniques, it is impossible to achieve 100% purity for separating a mixture; secondly, separation can continue infinitely without an endpoint.
Review articles
Recent advances in bismuth-based photocatalysts: Environment and energy applications
Sijia Song, Zipeng Xing, Huanan Zhao, Zhenzi Li, Wei Zhou
2023, 8(5): 1232-1264. doi: 10.1016/j.gee.2022.04.004
Abstract HTML PDF
Abstract:
Photocatalysis is an effective way to solve the problems of environmental pollution and energy shortage. Numerous photocatalysts have been developed and various strategies have been proposed to improve the photocatalytic performance. Among them, Bi-based photocatalysts have become one of the most popular research topics due to their suitable band gaps, unique layered structures, and physicochemical properties. In this review, Bi-based photocatalysts (BiOX, BiVO4, Bi2S3, Bi2MoO6, and other Bi-based photocatalysts) have been summarized in the field of photocatalysis, including their applications of the removal of organic pollutants, hydrogen production, oxygen production etc. The preparation strategies on how to improve the photocatalytic performance and the possible photocatalytic mechanism are also summarized, which could supply new insights for fabricating high-efficient Bi-based photocatalysts. Finally, we summarize the current challenges and make a reasonable outlook on the future development direction of Bi-based photocatalysts.
Graphene-based electrocatalysts for advanced energy conversion
Pingping Yang, Xin Yang, Wenzhu Liu, Ruike Guo, Zufu Yao
2023, 8(5): 1265-1278. doi: 10.1016/j.gee.2022.06.008
Abstract HTML PDF
Abstract:
Graphene-based nanocatalysts have appealed much interest as advanced electrocatalysts toward energy conversion reactions due to their outstanding electrocatalytic performance from the distinctive chemical composites and strong synergistic effects. Aiming to better understand the role of graphene played in enhancing the catalytic performance and offer guidance for fabricating more efficient graphene-based electrocatalysts, we herein summarize the remarkable achievements of graphene-based electrocatalysts for energy-conversion-related reactions. Started by discussing applications of graphene in the electrocatalytic reactions, we have manifested the crucial role of graphene played in promoting the catalytic performance. Subsequently, many representative graphene-based catalyst hybrids for electrocatalytic reactions are also overviewed, showing many effective strategies for the fabrication of more efficient graphene-related materials for the practical application. Finally, the perspective insights and challenging issues are also concluded to provide directions for the future development.
Recent advanced development of stabilizing sodium metal anodes
Liyu Zhu, Yucheng Li, Jingyang Zhao, Jing Liu, Luying Wang, Jiandu Lei
2023, 8(5): 1279-1307. doi: 10.1016/j.gee.2022.06.010
Abstract HTML PDF
Abstract:
As the application of next-generation energy storage systems continues to expand, rechargeable secondary batteries with enhanced energy density and safety are imperative for energy iteration. Sodium-ion batteries (SIBs) have attracted extensive attention and are recognized as ideal candidates for large-scale energy storage due to the abundant sodium resources and low cost. Sodium metal anodes (SMAs) have been considered as one of the most attractive anode materials for SIBs owing to their high specific capacity (1166 mAh g−1), low redox potential, and abundant natural resources. However, the uncontrollable dendrite growth and inevitable side reactions on SMA lead to the continuous deterioration of the electrochemical performance, causing serious safety concerns and limiting their practical application in the future. Therefore, the construction of stable dendrite-free SMAs is a pressing problem for advanced sodium metal batteries (SMBs). In this review, we comprehensively summarize the research progress in suppressing the formation of sodium dendrite, including artificial solid electrolyte interphase (SEI), liquid electrolyte modification, three-dimensional (3D) host materials, and solid-state electrolyte. Additionally, key aspects and prospects of future research directions for SMAs are highlighted. We hope that this timely review can provide an overall picture of sodium protection strategies and stimulate more research in the future.
High surface area biocarbon monoliths for methane storage
Elizabeth Michaelis, Renfeng Nie, Douglas Austin, Yanfeng Yue
2023, 8(5): 1308-1324. doi: 10.1016/j.gee.2022.07.005
Abstract HTML PDF
Abstract:
New energy sources that reduce the volume of harmful gases such as SOx and NOx released into the atmosphere are in constant development. Natural gas, primarily made up of methane, is being widely used as one reliable energy source for heating and electricity generation due to its high combustion value. Currently, natural gas accounts for a large portion of electricity generation and chemical feedstock in manufacturing plastics and other commercially important organic chemicals. In the near future, natural gas will be widely used as a fuel for vehicles. Therefore, a practical storage device for its storage and transportation is very beneficial to the deployment of natural gas as an energy source for new technologies. In this tutorial review, biomaterials-based carbon monoliths (CMs), one kind of carbonaceous material, was reviewed as an adsorbent for natural gas (methane) adsorption and storage.
Prelithiation strategies for silicon-based anode in high energy density lithium-ion battery
Tianqi Jia, Geng Zhong, Yao Lv, Nanrui Li, Yanru Liu, Xiaoliang Yu, Jinshuo Zou, Zhen Chen, Lele Peng, Feiyu Kang, Yidan Cao
2023, 8(5): 1325-1340. doi: 10.1016/j.gee.2022.08.005
Abstract HTML PDF
Abstract:
Green energy storage devices play vital roles in reducing fossil fuel emissions and achieving carbon neutrality by 2050. Growing markets for portable electronics and electric vehicles create tremendous demand for advanced lithium-ion batteries (LIBs) with high power and energy density, and novel electrode material with high capacity and energy density is one of the keys to next-generation LIBs. Silicon-based materials, with high specific capacity, abundant natural resources, high-level safety and environmental friendliness, are quite promising alternative anode materials. However, significant volume expansion and redundant side reactions with electrolytes lead to active lithium loss and decreased coulombic efficiency (CE) of silicon-based material, which hinders the commercial application of silicon-based anode. Prelithiation, pre-embedding extra lithium ions in the electrodes, is a promising approach to replenish the lithium loss during cycling. Recent progress on prelithiation strategies for silicon-based anode, including electrochemical method, chemical method, direct contact method, and active material method, and their practical potentials are reviewed and prospected here. The development of advanced Si-based material and prelithiation technologies is expected to provide promising approaches for the large-scale application of silicon-based materials.
Novel high-entropy oxides for energy storage and conversion: From fundamentals to practical applications
Zi-Yu Liu, Yu Liu, Yujie Xu, Hualiang Zhang, Zongping Shao, Zhenbin Wang, Haisheng Chen
2023, 8(5): 1341-1357. doi: 10.1016/j.gee.2023.04.007
Abstract HTML PDF
Abstract:
High-entropy oxides (HEOs) are gaining prominence in the field of electrochemistry due to their distinctive structural characteristics, which give rise to their advanced stable and modifiable functional properties. This review presents fundamental preparations, incidental characterizations, and typical structures of HEOs. The prospective applications of HEOs in various electrochemical aspects of electrocatalysis and energy conversion-storage are also summarized, including recent developments and the general trend of HEO structure design in the catalysis containing oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), supercapacitors (SC), lithium-ion batteries (LIBs), solid oxide fuel cells (SOFCs), and so forth. Moreover, this review notes some apparent challenges and multiple opportunities for the use of HEOs in the wide field of energy to further guide the development of practical applications. The influence of entropy is significant, and high-entropy oxides are expected to drive the improvement of energy science and technology in the near future.
Research papers
Facile synthesis of hydrochar-supported catalysts from glucose and its catalytic activity towards the production of functional amines
Xiuzheng Zhuang, Jianguo Liu, Longlong Ma
2023, 8(5): 1358-1370. doi: 10.1016/j.gee.2022.01.012
Abstract HTML PDF
Abstract:
Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years, we developed two sustainable routes (i.e., the impregnation method and the one-pot synthesis) to prepare the hydrochar-supported catalysts and tested its catalytic performance on the reductive amination. Several techniques, such as TEM, XRD and XPS, were adopted to characterize the structural and catalytic features of samples. Results indicated that the impregnation method favors the formation of outer-sphere surface complexes with porous structure as well as well-distributed metallic nanoparticles, while the one-pot synthesis tends to form the inner-sphere surface complexes with relatively smooth appearance and amorphous metals. This difference explains the better activity of catalysts prepared by the impregnation method which can selectively convert benzaldehyde to benzylamine with an excellent yield of 93.7% under the optimal reaction conditions; in contrast, the catalyst prepared by the one-pot synthesis only exhibits a low selectivity near to zero. Furthermore, the gram-scale test catalyzed by the same catalysts exhibits a similar yield of benzylamine in comparison to its smaller scale, which is comparable to the previously reported heterogeneous noble-based catalysts. More surprisingly, the prepared catalysts can be expediently recycled by a magnetic bar and remain the satisfying catalytic activity after reusing up to five times. In conclusion, these developed catalysts enable the synthesis of functional amines with excellent selectivity and carbon balance, proving cost-effective and sustainable access to the wide application of reductive amination.
Accurate quantification of TiO2(B)'s phase purity via Raman spectroscopy
Jiamiao Ran, Hui Liu, Hongliang Dong, Peng Gao, Haowei Cheng, Jianing Xu, Hailun Wang, Zixing Wang, Qingfeng Fu, Jiaxu Yan, Jilei Liu
2023, 8(5): 1371-1379. doi: 10.1016/j.gee.2022.02.008
Abstract HTML PDF
Abstract:
Bronze phase titanium dioxide (TiO2(B)) could be a promising high-power anode for lithium ion battery. However, TiO2(B) is a metastable material, so the as-synthesized samples are inevitably accompanied by the existence of anatase phases. It has been found that the TiO2(B)'s purity is positively correlated with its electrochemical performance. Herein, we have established an accurate quantification of the TiO2(B)/anatase ratio, by figuring out the function between the purity of TiO2(B) phase in the high purity range and its Raman spectra features in combination of the calibration by the synchrotron radiation X-ray diffraction (XRD). Compared with the time-consuming electrochemical method, the rapid, sensitive and non-destructive features of Raman spectroscopy have made it a promising candidate for determining the purity of TiO2(B). Further, the correlations developed in this work should be instructive in synthesizing pure TiO2(B) and furthermore optimizing its electrochemical charge storage properties.
Paper-based aqueous Al ion battery with water-in-salt electrolyte
Yifei Wang, Wending Pan, Kee Wah Leong, Yingguang Zhang, Xiaolong Zhao, Shijing Luo, Dennis Y. C. Leung
2023, 8(5): 1380-1388. doi: 10.1016/j.gee.2021.10.001
Abstract HTML PDF
Abstract:
Low-cost, flexible and safe battery technology is the key to the widespread usage of wearable electronics, among which the aqueous Al ion battery with water-in-salt electrolyte is a promising candidate. In this work, a flexible aqueous Al ion battery is developed using cellulose paper as substrate. The water-in-salt electrolyte is stored inside the paper, while the electrodes are either printed or attached on the paper surface, leading to a lightweight and thin-film battery prototype. Currently, this battery can tolerate a charge and discharge rate as high as 4 A g−1 without losing its storage capacity. The charge voltage is around 2.2 V, while the discharge plateau of 1.6-1.8 V is among the highest in reported aqueous Al ion batteries, together with a high discharge specific capacity of ~140 mAh g−1. However, due to the water electrolysis side reaction, the faradaic efficiency can only reach 85% with a cycle life of 250 due to the dry out of electrolyte. Benefited from using flexible materials and aqueous electrolyte, this paper-based Al ion battery can tolerate various deformations such as bending, rolling and even puncturing without losing its performance. When two single cells are connected in series, the battery pack can provide a charge voltage of 4.3 V and a discharge plateau as high as 3-3.6 V, which are very close to commercial Li ion batteries. Such a cheap, flexible and safe battery technology may be widely applied in low-cost and large-quantity applications, such as RFID tags, smart packages and wearable biosensors in the future.
Tailor-made microstructures lead to high-performance robust PEO membrane for CO2 capture via green fabrication technique
Wei-Shi Sun, Ming-Jie Yin, Wen-Hai Zhang, Shuo Li, Naixin Wang, Quan-Fu An
2023, 8(5): 1389-1397. doi: 10.1016/j.gee.2022.01.016
Abstract HTML PDF
Abstract:
Emerging excessive greenhouse gas emissions pose great threats to the ecosystem, which thus requires efficient CO2 capture to mitigate the disastrous issue. In this report, large molecular size bisphenol A ethoxylate diacrylate (BPA) was employed to crosslink poly (ethylene glycol) methyl ether acrylate (PEGMEA) via the green and rapid UV polymerization strategy. The microstructure of such-prepared membrane could be conveniently tailored by tuning the ratio of the two prepolymers, aiming at obtaining the optimized microstructures with suitable mesh size and PEO sol content, which was approved by a novel low-field nuclear magnetic resonance technique. The optimum membrane overcomes the trade-off challenge: dense microstructures lower the gas permeability while loose microstructures lower high-pressure-resistance capacity, realizing a high CO2 permeability of 1711 Barrer and 100-h long-term running stability under 15 atm. The proposed membrane fabrication approach, hence, opens a novel gate for developing high-performance robust membranes for CO2 capture.
3D inner-outer asymmetric sponge for enormous-volume emulsion wastewater treatment based on a new “demulsification-transport” mechanism
Ruixiang Qu, Shuaiheng Zhao, Na Liu, Xiangyu Li, Huajun Zhai, Ya'nan Liu, Yen Wei, Lin Feng
2023, 8(5): 1398-1408. doi: 10.1016/j.gee.2022.02.001
Abstract HTML PDF
Abstract:
Although oily wastewater treatment realized by superwetting materials has attracted heightened attention in recent years, how to treat enormous-volume emulsion wastewater is still a tough problem, which is ascribed to the emulsion accumulation. Herein, to address this problem, a material is presented by subtly integrating chemical demulsification and 3D inner-outer asymmetric wettability to a sponge substrate, and thus wettability gradient-driven oil directional transport for achieving unprecedented enormous-volume emulsion wastewater treatment is realized based on a “demulsification-transport” mechanism. The maximum treatment volume realized by the sponge is as large as 3 L (2.08 × 104 L per cubic meter of the sponge) in one cycle, which is about 100 times of the reported materials. Besides, owing to the large pore size of the sponge, 9000 L m2 h−1 (LMH) separation flux and 99.5% separation efficiency are realized simultaneously, which overcomes the trade-off dilemma. Such a 3D inner-outer asymmetric sponge displaying unprecedented advantage in the treatment volume can promote the development of the oily wastewater treatment field, as well as expand the application prospects of superwetting materials, especially in continuous water treatment.
NMR diffusion analysis of catalytic conversion mixtures from lignocellulose biomass using PSYCHE-iDOSY
Qi Zhao, Christian Marcus Pedersen, Jiamin Wang, Rui Liu, Yuanli Zhang, Xiuyin Yan, Zhenzhou Zhang, Xianglin Hou, Yingxiong Wang
2023, 8(5): 1409-1416. doi: 10.1016/j.gee.2022.02.003
Abstract HTML PDF
Abstract:
The component analysis and structure characterization of complex mixtures of biomass conversion remain a challenging work. Hence, developing effective and easy to use techniques is necessary. Diffusion-ordered NMR spectroscopy (DOSY) is a non-selective and non-invasive method capable of achieving pseudo-separation and structure assignments of individual compounds from biomass mixtures by providing diffusion coefficients (D) of the components. However, the conventional 1H DOSY NMR is limited by crowded resonances when analyzing complex mixtures containing similar chemical structure resulting in similar coefficient. Herein we describe the application of an advanced diffusion NMR method, Pure Shift Yielded by CHirp Excitation DOSY (PSYCHE-iDOSY), which can record high-resolution signal diffusion spectra efficiently separating compounds in model and genuine mixture samples from cellulose, hemicellulose and lignin. Complicated sets of isomers (d-glucose/d-fructose/d-mannose and 1,2-/1,5-pentadiol), homologous compounds (ethylene glycol and 1,2-propylene glycol), model compounds of lignin, and a genuine reaction system (furfuryl alcohol hydrogenolysis with ring opening) were successfully separated in the diffusion dimension. The results show that the ultrahigh-resolution DOSY technique is capable of detecting and pseudo-separating the mixture components of C5/C6 sugar conversion products and its derivative hydrogenation/hydrogenolysis from lignocellulose biomass.
Manipulating oxygenate adsorption on N-doped carbon by coupling with CoSn alloy for bifunctional oxygen electrocatalyst
Chenlong Dong, Xilin Zhang, Shaoning Zhang, Siwei Zhao, Xueyu Lin, Xin Wang, Yajing Zhang, Fuqiang Huang
2023, 8(5): 1417-1428. doi: 10.1016/j.gee.2022.02.005
Abstract HTML PDF
Abstract:
Highly active bifunctional oxygen electrocatalysts accelerate the development of high-performance Zn-air battery, but suffer from the mismatched activities of oxygen evolution reaction (OER) and oxygen reduced reaction (ORR). Herein, highly integrated bifunctional oxygen electrocatalysts, cobalt-tin alloys coated by nitrogen doped carbon (CoSn@NC) are prepared by MOFs-derived method. In this hybrid catalyst, the binary CoSn nanoalloys mainly contribute to highly active OER process while the Co (or Sn)−N−C serves as ORR active sites. Rational interaction between CoSn and NC donates more rapid reaction kinetics than Pt/C (ORR) and IrO2 (OER). Such CoSn@NC holds a promise as air-cathode electrocatalyst in Zn-air battery, superior to Pt/C + IrO2 catalyst. First-principles calculations predict that CoSn alloys can upgrade charge redistribution on NC and promote the transfer to reactants, thus optimizing the adsorption strength of oxygen-containing intermediates to boost the overall reactivity. The tuning of oxygenate adsorption by interactions between alloy and heteroatom-doped carbon can guide the design of bifunctional oxygen electrocatalysts.
Crystal plane induced in-situ electrochemical activation of manganese-based cathode enable long-term aqueous zinc-ion batteries
Yuxin Gao, Jiang Zhou, Liping Qin, Zhenming Xu, Zhexuan Liu, Liangbing Wang, Xinxin Cao, Guozhao Fang, Shuquan Liang
2023, 8(5): 1429-1436. doi: 10.1016/j.gee.2022.02.009
Abstract HTML PDF
Abstract:
Rapid capacity decay and sluggish reaction kinetics are major barriers hindering the applications of manganese-based cathode materials for aqueous zinc-ion batteries. Herein, the effects of crystal plane on the in-situ transformation behavior and electrochemical performance of manganese-based cathode is discussed. A comprehensive discussion manifests that the exposed (100) crystal plane is beneficial to the phase transformation from tunnel-structured MnO2 to layer-structured ZnMn3O7·3H2O, which plays a critical role for the high reactivity, high capacity, fast diffusion kinetics and long cycling stability. Additionally, a two-stage zinc storage mechanism can be demonstrated, involving continuous activation reaction and phase transition reaction. As expected, it exhibits a high capacity of 275 mAh g−1 at 100 mA g−1, a superior durability over 1000 cycles and good rate capability. This study may open new windows toward developing advanced cathodes for ZIBs, and facilitate the applications of ZIBs in large-scale energy storage system.
Enhancing O2 electroreduction to H2O on Ag/MnO2-CHNTs by boosting a four-electron catalytic pathway
Aiai Zhang, Yang Liu, Caixia Li, Lei Xue, Ze Liu, Jinfang Wu, Shanghong Zeng
2023, 8(5): 1437-1449. doi: 10.1016/j.gee.2022.02.010
Abstract HTML PDF
Abstract:
A fundamental question in the oxygen reduction reaction (ORR) is how to rationally control the electrocatalytic selectivity for opening a four-electron reaction pathway. However, it still lacks direct experimental evidence to understand the reaction mechanism. This work unravels that Ag nanoparticles and carbonizing halloysite nanotubes (CHNTs) can trigger the construction of oxygen defects in the MnO2, which contribute to the generation of active sites. The Ag/MnO2-CHNTs delivers a superior activity toward ORR with high onset potential, half-wave potential, diffusion-limited current density, long-term durability and methanol tolerance. More importantly, combined with density functional theory calculations, triggering manganese dioxide defects upon the introduction of Ag nanoparticles and CHNTs can alter the electrocatalytic pathway from a two-electron to a direct four-electron direction for ORR, which is the nature of enhanced ORR activity. Based on the analysis of the results, this finding points out a very effective approach for exploring catalysts with the improved performance and durability for ORR reaction.
Mo/Fe bimetallic pyrophosphates derived from Prussian blue analogues for rapid electrocatalytic oxygen evolution
Jingyi Wang, Jiajia Huang, Siyu Zhao, Ivan P. Parkin, Zhihong Tian, Feili Lai, Tianxi Liu, Guanjie He
2023, 8(5): 1450-1458. doi: 10.1016/j.gee.2022.02.014
Abstract HTML PDF
Abstract:
Efficient and stable oxygen evolution electrocatalysts are indispensable for industrial applications of water splitting and hydrogen production. Herein, a simple and practical method was applied to fabricate (Mo, Fe)P2O7@NF electrocatalyst by directly growing Mo/Fe bimetallic pyrophosphate derived from Prussian blue analogues on three-dimensional porous current collector. In alkaline media, the developed material possesses good hydrophilic features and exhibits best-in-class oxygen evolution reaction (OER) performances. Surprisingly, the (Mo, Fe)P2O7@NF only requires overpotentials of 250 and 290 mV to deliver 100 and 600 mA cm−2 in 1 mol L−1 KOH, respectively. Furthermore, the (Mo, Fe)P2O7@NF shows outstanding performances in alkaline salty water and 1 mol L−1 high purity KOH. A worthwhile pathway is provided to combine bimetallic pyrophosphate with commercial Ni foam to form robust electrocatalysts for stable electrocatalytic OER, which has a positive impact on both hydrogen energy application and environmental restoration.
Boosting extraction of Pb in contaminated soil via interfacial solar evaporation of multifunctional sponge
Pan Wu, Xuan Wu, Yida Wang, Jingyuan Zhao, Haolan Xu, Gary Owens
2023, 8(5): 1459-1468. doi: 10.1016/j.gee.2022.03.002
Abstract HTML PDF
Abstract:
Interfacial solar water evaporation is a reliable way to accelerate water evaporation and contaminant remediation. Embracing the recent advance in photothermal technology, a functional sponge was prepared by coating a sodium alginate (SA) impregnated sponge with a surface layer of reduced graphene oxide (rGO) to act as a photothermal conversion medium and then subsequently evaluated for its ability to enhance Pb extraction from contaminated soil driven by interfacial solar evaporation. The SA loaded sponge had a Pb adsorption capacity of 107.4 mg g−1. Coating the top surface of the SA sponge with rGO increased water evaporation performance to 1.81 kg m−2 h−1 in soil media under one sun illumination and with a wind velocity of 2 m s−1. Over 12 continuous days of indoor evaporation testing, the Pb extraction efficiency was increased by 22.0% under 1 sun illumination relative to that observed without illumination. Subsequently, Pb extraction was further improved by 48.9% under outdoor evaporation conditions compared to indoor conditions. Overall, this initial work shows the significant potential of interfacial solar evaporation technologies for Pb contaminated soil remediation, which should also be applicable to a variety of other environmental contaminants.
KVPO4F/carbon nanocomposite with highly accessible active sites and robust chemical bonds for advanced potassium-ion batteries
Jianzhi Xu, Liping Duan, Jiaying Liao, Haowei Tang, Jun Lin, Xiaosi Zhou
2023, 8(5): 1469-1478. doi: 10.1016/j.gee.2022.12.007
Abstract HTML PDF
Abstract:
KVPO4F (KVPF) has been extensively investigated as the potential cathode material for potassium-ion batteries (PIBs) owing to its high theoretical capacity, superior operating voltage, and three-dimensional K+ conduction pathway. Nevertheless, the electrochemical behavior of KVPF is limited by the inherent poor electronic conductivity of the phosphate framework and unstable electrode/electrolyte interface. To address the above issues, this work proposes an infiltration-calcination method to confine the in-situ grown KVPF into the mesoporous carbon CMK-3 (denoted KVPF@CMK-3). The assembled KVPF@CMK-3 nanocomposite features three-dimensional interconnected carbon channels, which not only offer abundant active sites and significantly accelerate K+/electron transport, but also prevent the growth of KVPF nanoparticle agglomerates, hence stabilizing the structure of the material. Additionally, V-F-C bonds are created at the interface of KVPF and CMK-3, which reduce the loss of F and stabilize the electrode interface. Thus, when tested as a cathode material for PIBs, the KVPF@CMK-3 nanocomposite delivers superior reversible capacitiy (103.2 mAh g−1 at 0.2 C), outstanding rate performance (90.1 mAh g−1 at 20 C), and steady cycling performance (92.2 mAh g−1 at 10 C and with the retention of 88.2% after 500 cycles). Moreover, its potassium storage mechanism is further examined by ex-situ XRD and ex-situ XPS techniques. The above synthetic strategy demonstrates the potential of KVPF@CMK-3 to be applied as the cathode for PIBs.
Efficient conversion of lignin waste and self-assembly synthesis of C@MnCo2O4 for asymmetric supercapacitors with high energy density
Jiahui Mu, Cuihuan Li, Jiankang Zhang, Xianliang Song, Sheng Chen, Feng Xu
2023, 8(5): 1479-1487. doi: 10.1016/j.gee.2022.09.010
Abstract HTML PDF
Abstract:
Lignin waste from the papermaking and biorefineries industry is a significantly promising renewable resource to prepare advanced carbon materials for diverse applications, such as the electrodes of supercapacitors; however, the improvement of their energy density remains a challenge. Here, we design a green and universal approach to prepare the composite electrode material, which is composed of lignin-phenol-formaldehyde resins derived hierarchical porous carbon (LR-HPC) as conductive skeletons and the self-assembly manganese cobaltite (MnCo2O4) nanocrystals as active sites. The synthesized C@MnCo2O4 composite has an abundant porous structure and superior electronic conductivity, allowing for more charge/electron mass transfer channels and active sites for the redox reactions. The composite shows excellent electrochemical performance, such as the maximum specific capacitance of ~726 mF cm−2 at 0.5 mV s−1, due to the significantly enhanced interactive interface between LR-HPC and MnCo2O4 crystals. The assembled all-solid-state asymmetric supercapacitor, with the LR-HPC and C@MnCo2O4 as cathode and anode, respectively, exhibits the highest volumetric energy density of 0.68 mWh cm−3 at a power density of 8.2 mW cm−3. Moreover, this device shows a high capacity retention ratio of ~87.6% at 5 mA cm−2 after 5000 cycles.
Integration of pore structure modulation and B, N co-doping for enhanced capacitance deionization of biomass-derived carbon
Yao Qiu, Chunjie Zhang, Rui Zhang, Zhiyuan Liu, Huazeng Yang, Shuai Qi, Yongzhao Hou, Guangwu Wen, Jilei Liu, Dong Wang
2023, 8(5): 1488-1500. doi: 10.1016/j.gee.2023.01.005
Abstract HTML PDF
Abstract:
Biomass-derived carbon has demonstrated great potentials as advanced electrode for capacitive deionization (CDI), owing to good electroconductivity, easy availability, intrinsic pores/channels. However, conventional simple pyrolysis of biomass always generates inadequate porosity with limited surface area. Moreover, biomass-derived carbon also suffers from poor wettability and single physical adsorption of ions, resulting in limited desalination performance. Herein, pore structure optimization and element co-doping are integrated on banana peels (BP)-derived carbon to construct hierarchically porous and B, N co-doped carbon with large ions-accessible surface area. A unique expansion-activation (EA) strategy is proposed to modulate the porosity and specific surface area of carbon. Furthermore, B, N co-doping could increase the ions-accessible sites with improved hydrophilicity, and promote ions adsorption. Benefitting from the synergistic effect of hierarchical porosity and B, N co-doping, the resultant electrode manifest enhanced CDI performance for NaCl with large desalination capacity (29.5 mg g−1), high salt adsorption rate (6.2 mg g−1 min−1), and versatile adsorption ability for other salts. Density functional theory reveals the enhanced deionization mechanism by pore and B, N co-doping. This work proposes a facile EA strategy for pore structure modulation of biomass-derived carbon, and demonstrates great potentials of integrating pore and heteroatoms-doping on constructing high-performance CDI electrode.

Publish With GEE

Contact

  • Email：gee@ipe.ac.cn
  • Tel：010-82627075
  • Address：North 2nd street, Zhongguancun, Haidian District, Beijing, China

Links

京ICP备10002620号-1京公网安备 11010802039050号

Supported by: Beijing Renhe Information Technology Co. Ltd