Current Energy Storage Technologies Research Articles

Strain effect on TaSe2/Te2 monolayer as adsorption substrate in lithium–sulfur battery

Lithium-sulfur (Li–S) batteries, with their high theoretical specific capacity and energy density, are considered a promising alternative to current energy storage technologies. However, their practical application is hindered by the polysulfide shuttle effect, which leads to capacity fade and reduced coulombic efficiency. In this study we employs density functional theory (DFT) to explore the use of two-dimensional (2D) metallic transition metal dichalcogenides (TMDs), tantalum diselenide (TaSe2) and tantalum ditelluride (TaTe2), as anchoring materials for lithium polysulfides (LiPSs). Our findings reveal that these TMD monolayers exhibit a balanced binding affinity towards LiPSs, ranging from 1.20ev to 3.34eV (TaSe2) and from 2.35ev to 3.74eV (TaTe2). Notably, the decomposition barriers for Li2S on TaSe2 and TaTe2 are significantly lower than those of bulk Li2S with a value of 1.62eV and 1.54eV, suggesting these materials can facilitate rapid charge-discharge processes. The introduction of strain, simulating the expansion during lithiation, demonstrates that these monolayers maintain their adsorption capabilities, a crucial attribute for practical applications, with a increased decomposition barriers of 2.4eV(TaSe2) and 2.51eV(TaTe2). The catalytic activity of these monolayers for the sulfur reduction reaction (SRR) was evaluated, showing a spontaneous conversion mechanism for lithium-sulfur clusters, which is expected to enhance the overall performance of Li–S batteries. This study presents TaSe2 and TaTe2 as innovative and promising candidates for advanced Li–S battery applications, offering a perspective in addressing the critical challenges associated with the polysulfide shuttle effect.

Modulation of zinc deposition behaviour by electrostatically spun PAN-ZnTFSI fibre layer on separator for aqueous zinc ion batteries

Aqueous zinc ion batteries (AZIBs) are well-suited for current energy storage technologies due to their high safety and low cost. However, battery failures resulting from dendrites and side reactions restrict their widespread application. Here, we designed a polyacrylonitrile (PAN)-zinc trifluoromethanesulfonate (ZnTFSI) nanofibre synergistic glass fibre (PZ-GF) to modulate the interfacial deposition kinetics. The effective coordination of numerous CN functional groups within PZ, in conjunction with Zn2+, results in the homogeneous dispersion of the electric field across the electrode, which promotes the uniform deposition of Zn2+ on the zinc anode and thus significantly inhibits the rapid growth of zinc dendrites. ZnTFSI is hydrophilic and has strong hydrogen bonding interactions with the H2O molecule so that the separator can be used as a molecular sieve to regulate the flux of H2O, promote the desolvation of hydrated zinc ions, and inhibit side reactions.Tests of the initial nucleation overpotential of the symmetric battery and calculation of the activation energy reflect that PZ-GF has a smaller nucleation energy barrier and enhanced kinetic effect. And the zinc symmetric battery with PZ-GF film shows an ultra-long cycle stability of 1200 cycles with a capacity retention of 75 % even at 0.5 A g−1 for the Zn//VO2 full cells.

Compact, efficient, and affordable absorption Carnot battery for long-term renewable energy storage

The growing penetration of renewable energy poses significant challenges to the stability of the power grid, necessitating the development of advanced energy storage systems to facilitate power grid decarbonization with enhanced flexibility. Nonetheless, current energy storage technologies face obstacles including geographical constraints, high expenses, and short lifespans. In this work, a novel Carnot battery (power-heat-power conversion) based on absorption-desorption processes of hygroscopic salt solutions, absorption Carnot battery (ACB), is proposed for large-scale renewable energy storage with remarkable energy storage density (ESD), competitive round-trip efficiency (RTE), and negligible self-discharging rate (SDR). Through the integration of heat-generation, heat-storage, and power-generation sub-cycles into a single compact system, the ACB can save space and cost compared to previous Carnot batteries. A dynamic model is established with high accuracies to explore the characteristics of the proposed system. The dynamic temperatures, pressures, concentrations, mass flow rates, powers, and efficiencies of the ACB are analyzed to elucidate its energy conversion/storage mechanism. Based on the multi-objective optimization, the optimum operating concentration range of [45%, 60%] is determined, demonstrating the best comprehensive performance with an RTE of 45.80% and an ESD of 16.26 kWh/m3. Compared to the existing energy storage systems, the ACB stands out due to the competitive RTEs (30.5%–48.4%) and higher ESDs (7.6–21.8 kWh/m3). Even during an 80-day standby period, the ACB exhibits a small SDR of only 0.74%, which is significantly lower than that of Rankine pumped thermal energy storage (RPTES) at 33.01%. Despite the ACB yields a higher initial cost, it demonstrates a markedly lower levelized cost of storage (0.342 $/kWh) compared to the RPTES (0.749 $/kWh) because of its higher ESD, thus confirming the economic feasibility of the proposed system.

Assessing the value of hydrogen thermal energy storage and electric thermal energy storage in NEOM city

A large community such as NEOM City which is supposed to be powered only by wind and solar renewable energy requires a significant amount of energy storage. Given the limitations of the current energy storage technologies, from the total storable energy to the time this energy is stored, from the cost to the technology readiness level, it is important to provide assessments of continuing evolving alternative technologies. The cases of electric (external) thermal energy storage (eTES), and hydrogen thermal energy storage (hTES), are here considered. eTES is based on warming up a molten salt by using an electric resistance. The molten salt is then used to warm up a power cycle fluid for dispatchable energy production running a thermal power cycle. eTES suffers from round trip efficiency below 50 % but may handle a larger amount of energy at a lower cost compared to lithium-ion battery energy storage. eTES may benefit from integration with concentrated solar power with (internal) thermal energy storage. hTES is then based on green hydrogen production by electrolyzers, storage of the hydrogen in tanks, and combustion of the hydrogen to warm up a power cycle fluid for dispatchable energy production running a thermal power cycle. Of cost more difficult to estimate, also depending on the deployment of electrolyzers and round trip efficiencies below 50 %, hTES has the benefit to permit the storage of any amount of energy even over long time scales such as those needed to compensate for seasonal variability. Before electrolyzers provide the due amount of green hydrogen, the combustion power plant can be run with natural gas, delivering if not zero CO2 emission, certainly the lowest life cycle CO2 emission for dispatchable electricity at present. Finally, eTES and hTES can be coupled with each other, and also integrated with waste-to-energy (WTE) systems, for a more comprehensive and sustainable approach based on common thermal power cycles.

(Invited) Textile Composite Electrodes for Wearable Batteries and Beyond

Wearable energy storage devices are indispensable corner stones for future wearable electronics. Current energy storage technologies are based on materials and devices that are rigid, bulky, and heavy, making them difficult to wear. On the other hand, fibers are flexible and lightweight materials that can be assembled into different textiles and have been worn by human beings thousands of years. Different from conventional two-dimensional thin films and foils, the three-dimensional fibre and textile structures not only provide superior wearing ability, but also much larger surface areas. This talk will introduce how our research group makes use of the attributes of fibres for high-performance wearable energy storage devices. We will demonstrate the strategies and discuss the perspectives to modify fibers and textiles for making wearable capacitators and batteries with excellent mechanical durability, electrochemical stability, and high energy/power density. We will also show that the fibrous materials can significantly enhance the stability and energy density of battery for wearable applications and others such as Na battery.

Design and Optimization of a Super Capacitor-Based High-Speed Charging System for Electric Vehicles

In this study, the design and optimization of high-speed charging systems for supercapacitor banks are investigated to meet the fast charging needs of electric vehicles. The limitations of current energy storage technologies and the requirements for fast charging of electric vehicles are addressed. While examining the advantages and energy storage potentials of supercapacitors, appropriate capacity, and voltage levels are determined in the design process to increase the charging speed. Additionally, power electronic components and control strategies are discussed to enhance the efficiency of the charging system. These components and strategies aim to optimize the fast charging process by enabling supercapacitors to be charged with maximum efficiency. The effectiveness and optimization potential of the design are evaluated and discussed through simulations conducted using the Matlab/Simulink software program. This article emphasizes the significance of supercapacitor-based high-speed charging systems in meeting the fast charging needs of electric vehicles and provides a foundation for future advancements. With the progress of electric vehicle technologies, supercapacitor-based charging systems aim to enable faster and more efficient charging, thereby further popularizing the use of electric vehicles.

Logistics Pure Electric Vehicle Routing Based on GA-PSO Algorithm

Abstract:Based on current energy storage technologies such as batteries and fuel cells, the inherent battery capacity of electric vehicles puts constraints on their driving range and requires charging in the process of completing driving tasks. In this paper, with the current practical application in logistics industry as the background, from electric vehicle charging scheduling and path planning, a hybrid algorithm combining genetic-particle swarm algorithm is proposed to plan the best driving route for a group of electric logistics vehicles with vehicle load, vehicle battery life, charging facility location and customer time window as constraints and the total cost as the objective function. Based on the single distribution center, a more complex multi-distribution center electric vehicle path planning problem is considered. In this paper, multiple sets of Solomon VRPTW data sets are selected to test the prepared algorithm, and the results show that the algorithm can effectively plan the best distribution scheme.

Research on integrated micro-energy storage technology based on multi-type electrochemistry

Electrochemical energy storage is a process that utilizes chemical reactions to store and release electrical energy in the form of chemical energy. These include lead-acid, lithium-ion, flow, sodium-sulfur batteries, etc., while electrochemical energy storage materials and technologies are the keys to solving the utilization, conversion, and storage of clean energy. In order to solve the problem that the current energy storage technology has an extensive range of energy storage frequency fluctuations in the application process, this paper conducts research on a comprehensive micro-energy storage technology based on multi-type electrochemistry, which improves the stability of energy storage. Based on the introduction of multi-type electrochemical technology, MXene (Ti3C2) was selected as the dispersion liquid, and PVA was used as the gel electrolyte to complete both preparations. The device’s fabrication and assembly are completed based on calculating the rated power, rated capacity, and other parameters of the micro energy storage capacitor. Aiming at the ultra-low frequency oscillation problem that may exist in the energy storage process, this paper develops a micro energy storage control method that participates in primary frequency modulation. The comparison experiment proves that the frequency fluctuation of the new energy storage technology is within the controllable range in practical application, which can effectively improve the stability of energy storage.

TiC nanoparticles supported on free-standing carbon nanofibers enabled high-performance Lithium–Sulfur batteries

Lithium–sulfur (Li–S) batteries hold great promise for substituting current energy-storage technologies owing to their exceptional advantage in energy density. The main challenge in developing practical Li–S batteries is the lack of efficient sulfur host which can simultaneously suppress the shuttle effect and improve the redox kinetics. Polar host materials manifest chemisorptive properties for localizing the mobile polysulfide intermediates, being promising in inhibiting the shuttle effect; however, their poor intrinsic conductivity hinders their role in enhancing the redox kinetics of subsequent conversion reactions. In this regard, a conductive polar host material is highly desirable for efficient and long-life Li–S batteries. Herein, we design and develop a free-standing sulfur host consisted of carbon nanofibers decorated with titanium carbides nanoparticles (TiC/CNFs) for high performance Li–S batteries. Benefiting from the intrinsic chemical polarity and high electric conductivity of TiC, the chemisorption and conversion kinetics of lithium polysulfides are simultaneously promoted, leading to the greatly enhanced battery performance. For example, the S@TiC/CNFs composite cathode retains a high capacity of 672 mA h g−1 after 1000 cycles and an excellent rate performance of 938 mA h g−1 at 5 C. Impressively, even at a super high sulfur loading of 7 mg cm−2, the TiC/CNFs can retain a capacity of 5 mA h (630 mA h g−1) after 100 cycles, highlighting the advantages of the polar conductive sulfur host design for efficient conversion of lithium polysulfides.

Long-Lifespan Lithium Metal Batteries Enabled by a Hybrid Artificial Solid Electrolyte Interface Layer.

Lithium metal batteries based on metallic Li anodes have been recognized as competitive substitutes for current energy storage technologies due to their exceptional advantage in energy density. Nevertheless, their practical applications are greatly hindered by the safety concerns caused by lithium dendrites. Herein, we fabricate an artificial solid electrolyte interface (SEI) via a simple replacement reaction for the lithium anode (designated as LNA-Li) and demonstrate its effectiveness in suppressing the formation of lithium dendrites. The SEI is composed of LiF and nano-Ag. The former can facilitate the horizontal deposition of Li, while the latter can guide the uniform and dense lithium deposition. Benefiting from the synergetic effect of LiF and Ag, the LNA-Li anode exhibits excellent stability during long-term cycling. For example, the LNA-Li//LNA-Li symmetric cell can cycle stably for 1300 and 600 h at the current densities of 1 and 10 mA cm-2, respectively. Impressively, when matching with LiFePO4, the full cells can steadily cycle for 1000 times without obvious capacity attenuation. In addition, the modified LNA-Li anode coupled with the NCM cathode also exhibits good cycling performance.

The application of covalent organic frameworks in Lithium-Sulfur batteries: A mini review for current research progress.

Recently, how to enhance the energy density of rechargeable batteries dramatically is becoming a driving force in the field of energy storage research. Among the current energy storage technologies, the lithium-sulfur (Li-S) batteries are one of the most promising candidates for achieving high-capacity and commercial batteries. The theoretical energy density of Li-S batteries reaches to 2,600Wh kg-1 with the theoretical capacity of 1,675mAh g-1. Therefore, Li-S batteries are considered as the great potential for developing future energy storage technology. However, some of problems such as Li dendrites growth, the shuttle effect of sulfides and the electronic insulation feature of sulfur, have brought obstacles to the development of Li-S batteries. The covalent organic frameworks (COFs) are a series of porous materials with different topological structures, which show the versatile characteristics of high specific surface area, permanent pores, ordered porous channels and tunable internal structure. Potentially, their ordered channels and extended conjugated frameworks could facilitate rapid Li-ion diffusion and electron transport for the remarkable rate capability. On the basis of these merits, the COFs become the potential electrode materials to solve the above serious problems of Li-S batteries. In this mini review, we summarize the research progress of COFs utilized as electrode materials in the Li-S batteries, including the cathode, separator and anode materials. Accordingly, the outlook of COFs as electrodes for future development in Li-S batteries is also given.

(Invited) Textile Composite Electrodes for Wearable Batteries and Beyond

Wearable energy storage devices are indispensable corner stones for future wearable electronics. Current energy storage technologies are based on materials and devices that are rigid, bulky, and heavy, making them difficult to wear. On the other hand, fibers are flexible and lightweight materials that can be assembled into different textiles and have been worn by human beings thousands of years. Different from conventional two-dimensional thin films and foils, the three-dimensional fibre and textile structures not only provide superior wearing ability, but also much larger surface areas. This talk will introduce how our research group makes use of the attributes of fibres for high-performance wearable energy storage devices. We will demonstrate the strategies and discuss the perspectives to modify fibers and textiles for making wearable capacitators and batteries with excellent mechanical durability, electrochemical stability, and high energy/power density. We will also show that the fibrous materials can significantly enhance the stability and energy density of battery for wearable applications and others such as Na battery.

Compressed air energy storage capacity of offshore saline aquifers using isothermal cycling

Growth of intermittent offshore wind energy installations has led to a search for energy storage technologies able to provide temporal balancing of electricity generation and demand. Offshore compressed air energy storage (OCAES) is a proposed energy storage option that uses saline aquifers as storage reservoirs and isothermal thermodynamic cycles to inject and extract air. Here, we present a method to assess the round-trip efficiency of OCAES when considering the uncertainty of geophysical parameters and machinery performance and demonstrate it using the Baltimore Canyon Trough off the coast of the Mid-Atlantic United States. Our results show that OCAES round-trip efficiencies of 60–62 % could provide 8.1 TWh of storage in water depths less than 60 m. We also identify permeability and thickness as critical subsurface parameters, and show the need to develop isothermal cycles at commercial scales. At a projected capital cost of $61/kWh, isothermal OCAES compares well against current energy storage technologies.

(Invited, Digital Presentation) Fundamental Understanding and Challenges in Cathode Materials for Next Generation Li-Ion Batteries

Introducing high-performance Li-ion batteries in current energy storage technologies has great hope in achieving decarbonization goals for sustainable future. The impact of Li-ion batteries in current energy sector is huge, especially portable electronics to electric vehicles. With this energy demand, recently, researchers have been exploring the so-called “Li-rich anion redox” cathode chemistry, in which electrons stored on oxide anions are reversibly utilized during redox reaction along with conventional transition metal redox to obtain high energy storage capability.1-2 Compared to conventional cathodes, the anion redox cathode chemistry is not straightforward as it goes through a complex redox reaction pathway, leading to fundamental issues such as voltage fade, voltage hysteresis and irreversible oxygen release. However, these anionic redox reactions in transition metal oxide-based cathodes attained by extracting excess lithium ions have resulted in stability issues due to weak metal (M) – oxygen(O) ligand covalency.1 In order to increase the tightness between metal–ligand, an alternative strategy was investigated by replacing M–O framework with M–X (X- S, Se) ligands. Based on the experimental studies, it is found that the metal-ligand tunability is the key to achieve highly reversible chalcogen anion redox reactions in various Li based chalcogen cathode materials.3 Further, the lithiation delithiation reactions of cathodes are investigated using in-depth electrochemical analysis and the electronic as well as structural changes during electrochemical reactions are understood using detailed spectroscopy and microscopy characterization. Findings from this research will inspire Ni and Co free chalcogen cathode design and various functional materials in the pursuit of next-generation cathode materials. In parallel, this presentation will also focus on fundamental understanding and importance of fabricating rechargeable high-temperature Li-ion batteries for various demanding applications such as military applications, sensor applications, oil and gas industry drilling applications. In this work, high temperature compatible electrode materials are identified, and their electrode/electrolyte interfacial stability issues at different depth levels are understood using energy tunable X-ray photon electron spectroscopy and further visualized with advanced microscopy imaging. This proof-of-concept study will lead to a new paradigm for transforming ambient temperature Li-ion battery technology to high-temperature applications.

Polyoxometalate Ionic Sponge Enabled Dendrite-Free and Highly Stable Lithium Metal Anode.

Metallic lithium batteries are holding great promises for revolutionizing the current energy storage technologies. However, the formation of dendrite-like morphology of lithium deposition caused by uneven distribution of Li+ might cause severe safety concerns of batteries. In this study, a polyoxometalate (POM) cluster, H5 PMo10 V2 O40 (PMo10 V2 ), is added to the conventional electrolyte that can construct a lithium-rich layer and inhibit the growth of Li dendrites effectively. The Li-rich layer can fill any lack of lithium ions on the surface of the metal anode, making the electric field strength consistent across the anode surface, thereby inhibiting the formation of lithium dendrites. Consequently, a significantly prolonged cyclic lifespan is obtained for both Li/Li symmetric cells and Li/LiCoO2 (Li/LCO) full cells. The cells with LCO positive maintains a high reversible specific capacity of 108.5mAhg-1 after 300 cycles when electrolyte with PMo10 V2 additive is used, compared to 31.5mAhg-1 for the untreated electrolyte. The findings indicate that POMs endowed as "ionic sponge" can be widely deployed in lithium metal batteries.

In Situ Characterization of the Solid Electrolyte Interphase in Lithium Ion Batteries

The increasing global energy demand has fueled considerable effort into improving upon current energy storage technologies to keep in step with this demand. Improving current energy storage technologies, such as lithium ion batteries (LIBs), requires insight and understanding of the fundamentals of their operation. A key component of LIBs is the solid-electrolyte interphase (SEI), which develops at the interface between the electrode and the electrolyte as a result of reaction with, and degradation of, the battery electrolyte [1]. This passivating layer is vital to the operation and performance of batteries, but little is known of its exact structure since these electrode/electrolyte interfaces are buried deep within the battery, and so are difficult to “look” at using standard characterization techniques [2]. So-called “post-mortem” studies, which involve taking batteries apart inside a glove box, are methodologically simple, but may alter the SEI surface chemistry due to exposing highly reactive materials to contaminants inside a glove box.Here we introduce a platform for in situ characterization of electrode/electrolyte interfaces, capable of operation and disassembly of LIB components (anode, cathode and electrolyte) completely in situ without the need to transfer materials to a glove box prior to characterization. We demonstrate the capabilities of the platform using interface sensitive techniques, including data from one of the first lab-based hard X-ray photoelectron spectrometers, which is based at the Henry Royce Institute at the University of Manchester. Electrochemical data is also presented, demonstrating the electrochemical characterization abilities of the platform, and shows potential for extending beyond studies of LIB technology.

A review on the large-scale shipboard energy storage systems

Energy storage system is an essential equipment in ships, which can supply various kinds of shipboard loads. With the maturity of electric propulsion technology, all-electric ships have become the main trend of future ship design. In this context, the energy storage system will be responsible for multiple types of ship loads, instead of mainly responsible for auxiliary loads in the past, especially acting as a part of the ship’s power system and cooperating with ship’s main/auxiliary engines to improve the economic/environmental characteristics of ships. The change of role accelerates the integration of large-scale energy storage systems into ships, bringing a series of issues such as energy storage system state estimation, energy management, and optimization planning. This paper first classifies the current energy storage technologies, then introduces the structure of typical all-electric ships and points out the application scenarios of energy storage systems, and finally proposes several technical problems that need to be resolved after the large-capacity energy storage systems are connected to ships, namely : Distributed control of ship energy storage system, adaptive planning and optimization of ship energy storage system, and state estimation of ship energy storage system. This research has clarified the future roadmap for large-scale energy storage integration into electrified ships.

Toward High-Energy-Density Lithium Metal Batteries: Opportunities and Challenges for Solid Organic Electrolytes.

With increasing demands for safe, high capacity energy storage to support personal electronics, newer devices such as unmanned aerial vehicles, as well as the commercialization of electric vehicles, current energy storage technologies are facing increased challenges. Although alternative batteries have been intensively investigated, lithium (Li) batteries are still recognized as the preferred energy storage solution for the consumer electronics markets and next generation automobiles. However, the commercialized Li batteries still have disadvantages, such as low capacities, potential safety issues, and unfavorable cycling life. Therefore, the design and development of electromaterials toward high-energy-density, long-life-span Li batteries with improved safety is a focus for researchers in the field of energy materials. Herein, recent advances in the development of novel organic electrolytes are summarized toward solid-state Li batteries with higher energy density and improved safety. On the basis of new insights into ionic conduction and design principles of organic-based solid-state electrolytes, specific strategies toward developing these electrolytes for Li metal anodes, high-energy-density cathode materials (e.g., high voltage materials), as well as the optimization of cathode formulations are outlined. Finally, prospects for next generation solid-state electrolytes are also proposed.

Reduced-Graphene-Oxide-Guided Directional Growth of Planar Lithium Layers.

Rechargeable lithium (Li) metal batteries hold great promise for revolutionizing current energy-storage technologies. However, the uncontrollable growth of lithium dendrites impedes the service of Li anodes in high energy and safety batteries. There are numerous studies on Li anodes, yet little attention has been paid to the intrinsic electrocrystallization characteristics of Li metal and their underlying mechanisms. Herein, a guided growth of planar Li layers, instead of random Li dendrites, is achieved on self-assembled reduced graphene oxide (rGO). In situ optical observation is performed to monitor the morphology evolution of such a planar Li layer. Moreover, the underlying mechanism during electrodeposition/stripping is revealed using ab initio molecular dynamics simulations. The combined experiment and simulation results show that when Li atoms are deposited on rGO, each layer of Li atoms grows along (110) crystallographic plane of the Li crystals because of the fine in-plane lattice matching between Li and the rGO substrate, resulting in planar Li deposition. With this specific topographic characteristic, a highly flexible lithium-sulfur (Li-S) full cell with rGO-guided planar Li layers as the anode exhibits stable cycling performance and high specific energy and power densities. This work enriches the fundamental understanding of Li electrocrystallization without dendrites and provides guidance for practical applications.

Reversible solid oxide cell systems for integration with natural gas pipeline and carbon capture infrastructure for grid energy management

Electrical energy storage (EES) is necessary to enable greater penetration of renewables and as a grid-balancing solution, but current EES technologies suffer from capacity or geological limitations and high cost. Reversible solid oxide cells (ReSOCs) are an electrochemical energy conversion technology that can produce both electricity from fuel (gas-to-power) and fuel from electricity (power-to-gas), depending on resource availability and demand. Leveraging in situ C-O-H chemistry and operating at intermediate temperature (600°C) and elevated pressure (10–20 bar) enables these cells to be mildly exothermic, eliminating the need for external heat input or high over-potential (low-efficiency) operation during electrolysis mode. This operating strategy also results in higher methane production during electrolysis, facilitating easier integration with natural gas pipeline infrastructure over steam/hydrogen electrolytic processes.This study proposes a ReSOC system integrated with both natural gas pipeline and carbon capture and storage (CCS) infrastructure to render a flexible, grid energy management resource. In gas-to-power mode, the system takes natural gas from a pipeline to produce electricity. Un-utilized fuel is combusted with oxygen and expanded through a turbine to produce more power. The water in the exhaust is condensed, and the remaining carbon dioxide is compressed for tanker or pipeline transportation to a carbon sequestration site. In power-to-gas mode, carbon dioxide and water are co-electrolyzed in the stack to produce methane and hydrogen, which can be injected directly into a natural gas pipeline or further refined into a purer stream of methane. We explore system design concepts, performance, and cost of a 50 MWe ReSOC system. Results indicate that synthetic natural gas (92.0% methane) can be produced at $22.7/MMBTU with a lower heating value efficiency of 81%. Alternatively, a system that net meters produced syngas and operates in power producing mode 50% of the time can generate electricity at a levelized cost of 10.5 ¢/kWh with an efficiency of 69% (LHV), while producing exhaust that is 95.5% carbon dioxide at 40 bar. If the system operates disproportionally in gas-to-power mode the LCOE drops to near 6 ¢/kWh. The economic outlook for mature ReSOC systems presented herein are found to be competitive with current energy storage technologies and natural gas peaker plants.