Electrodes For Energy Storage Research Articles

A hierarchical Cu2SnO4@NiCo-LDH nanofilament structure as a new-potent electrode for energy storage

Our research continues to explore innovative, efficient electrode materials and new production processes for electrochemical devices. Supercapacitors remain at the forefront of energy storage solutions, thanks to their exceptional power density, cycling durability, and mechanical robustness. For the first time, we have developed a hierarchical Cu2SnO4@NiCo-LDH nanocomposite using a straightforward hydrothermal technique coupled with an annealing process on a nickel foam substrate. This study introduces the novel Cu2SnO4@NiCo-LDH (CSO@NC-LDH) material, distinguished by its unique nanofilament structure and impressive electrochemical properties, including a high specific capacitance of 2791.5 F g−1 at 1 A g−1. Additionally, we created an asymmetric supercapacitor using CSO@NC-LDH for the positive electrode and activated carbon (AC) for the negative electrode. This system showcases an outstanding energy density of 108.67 Wh kg−1 and a notable power density of 1.05 kW kg−1 at an operating voltage of 1.6 V. These exciting results highlight the promising potential of CSO@NC-LDH nanofilaments as advanced electrodes for next-generation energy storage devices.

High-performance supercapacitor electrodes for energy storage using activated carbons from argan husks, date seeds and olive stones

High-performance supercapacitor electrodes for energy storage using activated carbons from argan husks, date seeds and olive stones

Activated biomass-derived 3-dimensional porous graphene-like carbon for high-performance energy storage electrode materials

Activated biomass-derived 3-dimensional porous graphene-like carbon for high-performance energy storage electrode materials

The amorphous porous carbon incorporating 1D-nanofiber as electroactive biomass with integrated pyrolysis for high-performance symmetrical supercapacitors

Supercapacitors widely use electroactive biomass as a carbon electrode for energy conversion and storage. In this research, carbon electrodes were fabricated using Nipah mesocarp (NM) as the base material for symmetric supercapacitor cells. NM sample was physically and chemically activated using KOH 0.5 M and CO2 at varying temperatures of 700 °C, 800 °C, and 900 °C. Physical activation is integrated with the carbonization process in a nitrogen atmosphere. A sample obtained by subjecting CO2 to an activation temperature of 800 °C yields a high purity of 90 % carbon atoms with a 1D superstructure (nanofiber structure), which has a high specific surface area of 676 m2g−1 and a high specific capacitance of 300 Fg−1 at 1 Ag−1. Supercapacitors assembled using NM electroactive biomass can achieve a high power density of 146 W kg−1 and an energy density of 42 Wh kg−1 in a 1 M H2SO4. This electroactive biomass has great potential to be considered as an electrode material for energy storage devices or conversions that are abundantly available in the universe, renewable, and economical.

Manganese Oxide Gas Diffusion Electrode Conditioning and Electrochemical Doping for Reversible Oxygen Reduction/Evolution Reactions

Developing durable and active bifunctional gas diffusion electrodes for reversible oxygen reduction/evolution (ORR/OER) reaction catalysis is crucial yet challenging in the development of numerous electrochemical energy conversion systems, including regenerative fuel cells and rechargeable metal-air batteries. This research is focused on developing manganese oxide-based gas diffusion electrodes for reversible oxygen electrodes.Core-porous shell Mn/Mn3O4 (abbreviated as MnOx) nanoparticles (QSI) demonstrated increased ORR/OER activities compared to γ-MnO2 (EMD) and b-MnO2.[1] The unique behaviour of core-shell MnOx is attributed to the charge transfer between the low-valent Mn core and the high-valent Mn3O4 shell, thereby regenerating Mn(III) active sites through comproportionation.[1]The stability of transition-metal-based reversible oxygen electrodes remains a challenge. As shown in Figure 1, the deterioration of Mn/Mn3O4 during ORR and OER cycling can be attributed to three aspects: Mn active sites oxidation (Figure 1a), less active MnOx phase formation (Figure 1b), and material loss (carbon corrosion and dissolved MnO4 - formation) (Figure 1c).[2] As a result, the QSI MnOx electrode transformed from pristine to inactive status within 15 galvanostatic ORR/OER cycles. To improve the stability of the electrode, a set of in-situ electrochemical conditioning and electric field-driven metallic cation incorporation into MnOx GDE was investigated. Among the explored metal cations, the Ni2+ incorporation showed the most significant improvement in terms of activity and cyclic stability. The Ni-MnOx GDE demonstrated excellent stability for over 120 galvanostatic cycles at ±10 mA cm-2 in O2-saturated KOH without losing OER activity, surpassing the Pt/C-IrO2 benchmark.[3]These findings position the MnOx electrodes as promising and sustainable alternatives to precious metal-based electrodes for ORR/OER catalysis and provide valuable insights into designing reversible oxygen electrodes for energy conversion and storage in alkaline systems, contributing to a green future.[1] Pei, Y., Wilkinson, D. P., & Gyenge, E. L. Insights into the electrochemical behavior of manganese oxides as catalysts for the oxygen reduction and evolution reactions: monometallic core‐shell Mn/Mn3O4. Small, 2023, 19, 2204585.[2] Pei, Y., Wilkinson, D. P., & Gyenge, E. L. Gas Diffusion Electrode Design and Conditioning with Manganese (III/IV) Oxide Catalyst for Reversible Oxygen Reduction/Evolution Reactions. ACS Energy & Fuels (2023), 37, 23, 19278–19291.[3] Pei, Y., Wu, W. Y., Wilkinson, D. P., & Gyenge, E. L. High-Performance Reversible Oxygen Reduction/Evolution Gas Diffusion Electrodes with Multivalent Cation Doped Core-Shell Mn/Mn3O4 Catalysts. ChemElectroChem, in press. Figure 1

Design and Additive Manufacturing of Electrodes for Electrochemical Energy Storage

Supercapacitors exhibit rapid charge/discharge times and have attracted considerable attention within the automotive, aerospace, and telecommunication industries. The high electrical conductivity and surface area of porous carbons have been attractive for supercapacitor electrodes. Fabricating thick electrodes is one strategy to further increase energy density due to a higher volume fraction of active material. However, thick electrodes suffer from sluggish charged species transport. In this work, we investigate the use of computational optimization and additive manufacturing to design and fabricate thick porous electrodes with improved performance. Electrode performance was maximized by designing their morphologies via topology optimization and printing by projection micro stereolithography (PµSL) using commercial resin (PR48). The PR48 resin was then pyrolyzed (PR48-P) to create the final conductive electrode. The optimized PR48-P electrodes exhibited 99% improvement in capacitance compared to control electrodes printed with cubic lattice morphologies. To further improve performance, we formulated a resin combining graphene oxide (GO) and trimethylolpropane triacrylate (TMPTA). Electrodes printed with 3 wt% GO in TMPTA exhibited improved capacitance retention after pyrolysis compared to the PR48-P electrodes. This work demonstrates the enormous potential of leveraging topology optimization and additive manufacturing to resolve many challenges in the electrochemical storage and renewable energy regimes. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC Figure 1

Shape Optimization for Lithium-Ion Battery with Porous Electrodes

In this presentation, we introduce a gradient-based shape optimization framework to design porous electrodes for maximum energy storage. Lithium-ion batteries are becoming an increasingly important energy source and storage device. Large surface area that advocates high reaction rates often leads to small porosities that deteriorate electrochemical transport, which significantly restricts ion penetration depth, limiting the material utilization in planar electrodes. Consequently, architected electrodes are required to optimize performance.We consider a model with two materials, namely porous electrode and pure electrolyte. Density-based topology optimization with continuous material volume fraction has previously been implemented on lithium-ion battery system for both half-cell and full-cell model to maximizes its energy storage. Despite the capability of producing complex interdigitated structures, an appropriate penalization scheme for intermediate materials is required for the optimizer to provide near binary designs. Setting up such a penalization is often time-consuming due to the large number of design-dependent variables that affect the forward model differently. Alternatively, the shape optimization approach used in this work produces binary designs naturally by morphing conformal meshes, circumventing inaccuracies associated with fuzzy interfaces. Shape sensitivities are computed via the adjoint method and leveraging automatic differentiation. The optimization problem is solved using a nonlinear programming technique.In this presentation, we perform shape optimization on a half-cell model to maximize its energy storage when a fixed charging current is applied. We study multiple arrangements of physical parameters and compare their performance against a monolithic electrode. Both 2D and 3D results are presented.

(Invited) 3D Carbon-Based Hierarchical Electrodes for Energy Storage

: Carbon-based 3D hierarchical electrodes with appropriate spatial distributions of pores are expected to empower rapid and controllable electrochemical reactions. The ability to fabricate such an electrode, with tunable geometries comprised of continuous nano- and micro-conduits, allows simultaneous optimization of conversion capacity as well as reaction rate. Such manufacturability holds great potential to redefine the future of energy storage, electrocatalysis and chemical production for a sustainable future.In this presentation, I will outline two convergent strategies that involve the integration of additive manufacturing with several decades of advancements in nanomaterials synthesis, coupled with conventional pyrolysis – for creating such electrodes. The primary structure of 3D carbon-based electrodes was fabricated by either direct 3D writing, or the transition metal assisted pyrolysis of 3D-printed polymer templates. The secondary structure was established by employing bottom-up synthesis approaches: (a) SiO2 nanoparticle templates to create nanoscopic porous structures or (b) nanochannels formed through direct growth of carbon nanotubes. We have demonstrated that the primary and secondary structures can be formed by a single step. After monolithic integration of a tertiary structure to reveal sites for electrochemical conversion, these 3D architected electrodes offer impressive charge storage capacities while maintain excellent rate capability.By exploiting the short mass diffusion lengths, we have demonstrated that the new energy storage devices can operate at temperatures as low as -70°C without the requirement of a heater. Furthermore, the incorporation of a high loading of active materials in our 3D electrodes allows for concurrent enhancement of both energy density and power density. These scalable fabrication protocols address two critical challenges – sluggish mass transfer in 3D and the lack of accessible active sites, thereby offering a pathway to harness electrochemical reactions in 3D. This work offers an adaptable solution across a broad spectrum of industries.

Boosting supercapacitor performance: Sb2O3 nano-blocks on rGO sheets for enhanced energy storage

In this work, the synthesis of antimony(III) oxide (Sb2O3) nanoblocks/reduced graphene oxide (rGO) sheets was obtained by a straightforward hydrothermal method. Sb2O3/rGO composites were prepared with various ratios of rGO. The results indicated that the Sb2O3/15 mg rGO composite had remarkable electrochemical performance. It displayed a good electrochemical efficiency, with a high specific capacitance of 151.89 F g−1 at 1 A g−1. Furthermore, it demonstrated a significant cycling stability, retaining 80 % of its initial capacitance after 5 K charge/discharge cycles. A symmetric supercapacitor device was prepared using Sb2O3/15 mg rGO composite as the electrodes for both positive and negative ends. The device exhibited a high specific energy of 44.36 Wh kg−1 and a significant specific power of 850.76 W kg−1. Moreover, it maintained 5.025 Wh kg−1 at a specific power of 7.25 kW kg−1. These results indicated that the Sb2O3/15 mg rGO composite has the potential promising application as an energy-storage electrode material, as no investigations have been conducted on using Sb2O3/rGO as a supercapacitor electrode.

Ammonium Persulfate Derived N,S-Dual-Doped Graphene─A Versatile Bifunctional Electrode for Electrochemical Energy Storage and Sensing

Ammonium Persulfate Derived N,S-Dual-Doped Graphene─A Versatile Bifunctional Electrode for Electrochemical Energy Storage and Sensing

Investigating solvent effects on synthesizing novel cobalt hydroxide and fluoride complex from Co(BF4)2 as active materials of the battery supercapacitor hybrid

Metal-organic framework (MOF) derivatives with tunable pore structure and improved conductivity are intensively designed as electroactive materials. Incorporating structure directing agents (SDA) is beneficial for designing MOF derivatives with excellent electrochemical performances. Ammonium fluoroborate has been reported as an effective SDA, coupled with cobalt salt and 2-methylimidazole, to synthesize zeolitic imidazolate framework-67 (ZIF-67) derivatives for charge storage. However, the synthetic environment for growing cobalt-based active materials is relatively complex. In this study, cobalt tetrafluoroborate (Co(BF4)2) is proposed as a novel cobalt precursor, supplementing cobalt ions and acting as the SDA in a single chemical, to synthesize the cobalt-based electroactive material of energy storage electrodes. Interactions between solvent molecules and solutes play significant roles on the morphology, composition, and electrochemical performance of active materials. Deionized water, methanol and ethanol are used as precursor solvents to understand their effects on material and electrochemical properties. The optimal electrode presents a specific capacitance of 608.3 F/g at 20 mV/s, attributed to the highest electrochemical surface area and evident compositions of cobalt fluoride and hydroxide. A battery supercapacitor hybrid achieves the maximum energy density of 45 Wh/kg at 429 W/kg. The CF retention of 100% and Coulombic efficiency of 99% are achieved after 10,000 cycles.

Synthesis of reduced graphene oxide (rGO)/polyaniline (PANI) composite electrode for energy storage: Aqueous asymmetric supercapacitor

Composite materials have gained significant interest for energy storage applications due to their possible synergistic effects. This work describes the synthesis of reduced graphene oxide (rGO)/polyaniline (PANI) composite thin films using chemical bath deposition (CBD) method. A field-emission scanning electron microscope revealed that PANI spikes coated on rGO sheets in rGO/PANI composite. The electrochemical studies of a rGO/PANI composite electrode showed a specific capacitance (Cs) of 1130F/g Cs at a scan rate of 5 mV/s in 1 M H2SO4 electrolyte. The combined effect of rGO with PANI, a aqueous asymmetric supercapacitor device (ASC) with configuration of rGO/PANI/H2SO4/WO3 produced 97F/g Cs at a 5 mV/s scan rate and retained 82 % capacitance after 5,000 galvanostatic charge–discharge cycles. The ASC achieved a high specific energy of 23 Wh kg−1 at a specific power of 732 W kg−1. The electrochemical properties of rGO/PANI composite indicate a feasible method for creating asymmetric supercapacitors.

Bio-Inspired Energy Storage Electrode: Utilizing Co3O4 Hollow Spheres Derived from Sugarcane Bagasse Extract Synthesis Via Hydrothermal Route

Bio-Inspired Energy Storage Electrode: Utilizing Co3O4 Hollow Spheres Derived from Sugarcane Bagasse Extract Synthesis Via Hydrothermal Route

Synthesis of CuO/NiO nanostructured hybrid electrode for supercapacitors

Supercapacitors employing copper metal oxides have garnered significant interest due to their substantial theoretical capacity and expansive active surface area. However, the performance of pure copper oxide electrode materials cannot meet the high demands currently placed on supercapacitors. In this study, a convenient, efficient, two-step electrodeposition method was utilized to develop micro/nanostructures of CuO/NiO on nickel foam. The synthetic strategy optimizes the capacitive performance of the composite by adjusting the deposition parameters during the growth of the NiO film.The CuO/NiO electrode can provide an area ratio capacitance of up to 1435.62 mF/cm2, the addition of NiO improves the area capacitance of the electrode material and the capacitance retention after cycling. In addition, the CuO/NiO composite material has been used to prepare solid-state symmetric supercapacitors, the device can reach a maximum energy and power density of 31.89 μWh/cm2 and 2099.76 μW/cm2, respectively. These results suggest that CuO/NiO electrodes exhibit promising potential as energy storage electrode materials.

Direct Fabrication of 3D Electrodes Based on Graphene and Conducting Polymers for Supercapacitor Applications

AbstractThe development of commercially viable composite conducting polymer electrodes for energy storage is limited by the requirement of multiple and complex fabrication steps, low energy density, and poor cycling stability. In this work, a straightforward, economical, single‐step method is developed for creating densely packed nanostructured PEDOT/graphene composite material demonstrating its application as an electrode for supercapacitors. The electrode achieved the highest mass loading reported so far in the literature for composite vapor phase polymerized PEDOT/rGO using aqueous FeCl3 (25.2 mg cm−2), and displayed an ultrahigh areal capacitance of 4628.3 mF cm−2 at 0.5 mA cm−2. The symmetric two‐electrode setup displayed an energy density of 169.3 µWh cm−2 and a 70% capacitance retention after 70 000 cycles, showcasing its exceptional performance and durability.

Unlocking the critical roles of N, P Co-Doping in MXene for Lithium‐Oxygen Batteries: Elevated d‐Band center and expanded interlayer spacing

The design and fabrication of bifunctional catalysts with high electrocatalytic activity and stability are critical for developing highly reversible Li–O2 batteries (LOBs). Herein, the N, P co-doped MXene (NP-MXene) is prepared by one-step annealing method and evaluated as bifunctional catalyst for LOBs. The results suggest that the P doping plays a crucial role in increasing interlayer distance of MXene, thereby effectively providing more active sites, fast mass transfer, and ample space for the deposition/decomposition of Li2O2. Moreover, the N doping can significantly elevate the d-band center of Ti, thereby remarkably improving the adsorption of reaction intermediates and accelerating the deposition/decomposition of Li2O2 films. Consequently, the MXene-based LOBs deliver an ultrahigh specific capacity of 13,995 mAh/g at 500 mA g−1, a discharge/charge voltage gap of 0.89 V, and a cycle life up to 523 cycles with a limited capacity of 1000 mAh/g at 500 mA g−1. Impressively, the as-fabricated flexible LOBs with NP-MXene cathode display excellent cycling stability and ability to continuously power LEDs even after bending. Our findings pave the road of heteroatom doped MXenes as next-generation electrodes for high-performance energy storage and conversion systems.

In situ synthesis of M (Fe, Cu, Co and Ni)-MOF@MXene composites for enhanced specific capacitance and cyclic stability in supercapacitor electrodes

In this study, an in situ method was developed to synthesize a series of uniform 3D MOFs (Fe-, Cu-, Co-, Ni)-BTC@2D MXene (Ti3C2Tx) composites, and the experimental results show that a typical sample of Ni-MOF@MX 2 exhibits the highest specific capacitance of 1160.5 F·g−1 and 736 F·g−1 at a current density of 1 A·g−1 and 20 A·g−1, respectively, which is 2.3 times higher than the value of 320 F·g−1 at a current density of 20 A·g−1 on the bare Ni-MOF, and particularly maintains significant cyclic stability after 10,000 cycles at a high current density of 20 A·g−1. The improved electrochemical performance is ascribed to the synergistic interaction between layered MXene and MOFs, which were evidenced by experiments and theoretical calculations. The Ni-MOF@MX 2//AC asymmetric supercapacitor (ASC) device demonstrates a maximum energy density of 48.2 Wh kg−1 at 750 W kg−1. It retains 94 % capacity after 10,000 cycles. Moreover, the value still maintained at 23.3 Wh·kg−1 when elevating power density to 15000 W·kg−1. This indicates that the obtained MOF@MXene composites are probably alternative materials for supercapacitor electrodes in energy storage.

In-situ growth of novel iron oxide/iron organic framework composites as efficient electroactive materials of battery supercapacitor hybrids

Iron oxide (Fe2O3) with a high theoretical capacitance, wide potential ranges and easy availability has attracted much attentions as the electrode material of battery supercapacitor hybrids (BSH). Metal–organic framework (MOF) is one of the promising potential energy storage materials due to its large surface area and controllable pore structures. In this work, novel iron oxide/iron organic framework composites (Fe2O3/FeMOF) are in-situ grown on the Ni foam as efficient energy storage electrodes of BSH. By tuning the solvothermal durations, the morphology changes from random sizes of sheets, regular grown vertical sheets, to flower-like structures. The d-spacing also increases for the Fe2O3/FeMOF synthesized using longer solvothermal durations. The optimal Fe2O3/FeMOF electrode synthesized using 9 h shows a high areal capacitance of 10.97 F/cm2 along with an areal capacity of 5.49 F/cm2 at the current density of 35 mA/cm2, owing to the most regular growth of sheets, the large d-spacing, and the smallest charge-transfer resistances. A BSH composed of the Fe2O3/FeMOF positive electrode and a graphene negative electrode shows a maximum energy density of 0.76 mWh/cm2 at 22.5 mW/cm2. The excellent long-term cycling stability with the capacitance retention of 85% and Coulombic efficiency of 98% are also achieved after 10,000 charge/discharge cycles.

Research Progress of Functional Materials for Conversion of Agricultural Biomass Wastes

Excess agricultural biomass waste is increasing rapidly, leading to many environmental and governance issues. Therefore, increased attention has been paid to the recycling and value-added application of agricultural biomass waste. In recent years, the research of agricultural biomass waste utilization and derived functional materials has mainly included the following two aspects： ① the extraction of natural polymers and value-added applications and ② the direct preparation of new carbon-based materials, including adsorption, catalysis, energy storage electrode, and composite functional materials. The conversion of agricultural biomass waste into functional materials has been gradually realized and widely used. To enable industrial-scale production and the quality and safety of agricultural biomass waste derivatives and to develop highly feasible and cost-effective biomass waste conversion methods should be the focus of future studies.

Synthesis of 3D FeS embedded into N, S co–doped carbon nanotube/graphene framework for electrochemical application

Constantly striving to develop a facile and scalable way to construct advanced electrodes is essential for the advancement of batteries and electrocatalysis. In this work, an artful K2FeO4 oxidation cooperated with subsequent annealing process is proposed to produce 3D FeS embedded into N, S co–doped carbon nanotube/graphene (FeS/NSCNT/NSG) framework, which simultaneously achieves successful exfoliation of graphite, effective N, S co–doping and desirable integration of 3D framework by FeS and carbon matrix. The adopted procedure is simple, rapid and recyclable. Furthermore, the obtained FeS/NSCNT/NSG exhibits a unique 3D architecture, high doping level and favorable FeS dispersion status, thus displaying excellent performance towards lithium–ion batteries and oxygen evolution reaction. Undoubtedly, our research opens a new pathway for the development of advanced electrodes for energy storage and conversion devices.