Discharge Cycles Research Articles

A Comprehensive Flow–Mass–Thermal–Electrochemical Coupling Model for a VRFB Stack and Its Application in a Stack Temperature Control Strategy

In this work, a comprehensive multi-physics electrochemical hybrid stack model is developed for a vanadium redox flow battery (VRFB) stack considering electrolyte flow, mass transport, electrochemical reactions, shunt currents, and as heat generation and transfer simultaneously. Compared with other VRFB stack models, this model is more comprehensive in considering the influence of multiple factors. Based on the established model, the electrolyte flow rate distribution across cells in the stack is investigated. The distribution and variation in shunt currents, single-cell current and single-cell voltage are analyzed. The distribution and variation in temperature and heat generation and heat transfer are also researched. It can be found that the VRFB stack temperature will exceed 40 °C when operating at 60 A and 100 mA cm−2 at an ambient temperature of 30 °C, which will lead to electrolyte ion precipitation, affecting the performance and safety of the battery. To control the stack temperature below 40 °C, a new tank cooling control strategy is proposed, and the suitable starting cooling point and the controlled temperature are specified. Compared with the common room cooling strategy, the new tank cooling strategy reduces energy consumption by 27.18% during 20 charge–discharge cycles.

Characterization method of conductive film state of micro-cathode arc thrusters

Micro-Cathode Arc Thruster (μCAT) is an advanced electric propulsion system developed in the past decades to meet the maneuvering requirements of space microsatellites. However, the constraint on the its application is the short lifespan of the thruster. This is attributed to the conductive film, a key component of thruster discharge. In this study, we propose a measurement method for μCAT conductive film, and enables the evaluation of the evolution process of film thickness. The method is based on the four-probe resistivity testing theory and size effect fitting model, and establishes a method for characterizing the thickness and resistivity of μCAT conductive films. A comparison was made between the corrected resistivity test results of 1, 2, 5, and 10 μm film and the fitting results of the titanium film, revealing an error ofapproximately 10%. Additionally, a total of 2500 ignition experiments were conducted to verify the film thickness and resistance measurement of this method. This research serves as a valuable basis for the lifetime investigation of μCAT. Consequently, the thickness of the film progressively decreases with each discharge cycle, and the resistivity exhibits a corresponding increase due to the size effect. This method could be used as an effective method for exploring the μCAT lifespan and performance.

Breaking barriers of CeO2 in energy storage: Hydrothermal energized preparation of mesoporous carbon added CeO2 nanohybrids as supercapacitor electrodes

Inspired by the excellent physio-chemical properties of nano-sized materials, this study details the hydrothermal preparation and electrochemical characterization of mesoporous carbon added CeO2 nanostructures towards the energy storage applications. Cubic CeO2 is observed for the crystal structure and phase of the prepared materials. The formation of nano-sized (∼ 7 nm) quasi spherical-like structure is found from the TEM analysis and it is mainly ascribed to the combined effect of mesoporous carbon and hydrothermal treatment. The charge storage performance of the prepared composites is examined using three-electrode mode. The capacitive behaviour of mesoporous carbon is additionally supported for electrochemical performance in addition to the battery-like behavior of the CeO2 electrodes resulting in an increase of specific capacity by 102.6 %. Hybrid supercapacitor cell is devised and it could yield a specific energy of 31 W h kg–1 (562 W kg–1) and retain 81 % capacity after 3000 continuous charge discharge cycles. With this efficient composite, the future of energy storage may pave the way for more sustainable and powerful energy solutions.

Experimental Investigations into a Hybrid Energy Storage System Using Directly Connected Lead-Acid and Li-Ion Batteries

This paper presents experimental investigations into a hybrid energy storage system comprising directly parallel connected lead-acid and lithium batteries. This is achieved by the charge and discharge cycling of five hybrid battery configurations at rates of 0.2–1C, with a 10–50% depth of discharge (DoD) at 24 V and one at 48 V. The resulting data include the overall round-trip efficiency, transient currents, energy transfers between the strings, and the amount of energy discharged by each string across all systems. The general observation is that the round-trip efficiency drops from a maximum of around 94–95% in the first stages of the charge/discharge process, when only the Li-ion strings are active, to around 82–90% when the lead-acid strings reach a DoD of up to 50%. The most important parameters in the round-trip efficiency function are the ratio between the Li-ion and lead-acid energy available and the charge/discharge current. The energy transfer between the strings, caused by the transient currents, is negligible in the first stages of the discharge and then grows, with the DoD peaking at around 60% DoD. Finally, during the first stage of discharge, when only the Li-ion strings are active, the amount of energy discharged varies with the discharge C rate, decreasing to almost half at between 0.2 and 1C.

Construction of CNT@K+- doped δ-MnO2 by “killing two birds with one stone” strategy toward high-rate and stable aqueous zinc-ion batteries

Layered manganese dioxide (δ-MnO2) has garnered significant attention due to its exceptional potential as a cathode material in aqueous zinc-ion batteries. Nevertheless, the widespread adoption of δ-MnO2 in commercial applications remains hindered by challenges such as insufficient electrical conductivity and instability in its structural integrity throughout charge and discharge cycles. In this study, using KOH solution as the etchant, CNT@K+-doped δ-MnO2 (CNT@KMO) was successfully fabricated, where the CNTs enhance the transport of electron by establishing a conductive network, while the K+ from KOH serves as pillars to intercalate into the MnO2 interlayer, giving rise to a more stable structure. Consequently, the CNT@KMO electrode demonstrates an ideal reversible specific capacity of 306.1 mA h g-1 after 150 cycles at a current density of 0.5 A g-1 in a 2 M ZnSO4+0.2 M MnSO4 aqueous electrolyte. Furthermore, the electrode exhibits a respectable specific capacity of 100.8 mA h g-1 with a coulombic efficiency close to 100% at a current density of 5 A g-1 and exceptional cycling stability more than 2000 cycles. This novel synthesis strategy could pave the way for superior aqueous zinc ion batteries.

Effects of Co-doping on the microstructure and electrochemical performance of nickel vanadate (Ni3V2O8) electrode material for aqueous symmetric supercapacitor

Recently, there has been an increased focus on supercapacitors due to their reliable electrochemical energy storage capabilities. This study utilized an environmentally friendly facile hydrothermal method to prepare the nickel vanadate (NiVO) and cobalt-doped nickel vanadate (Co-doped Ni3V2O8) composite for supercapacitor applications. The prepared materials of pure and Co-doped Ni3V2O8 with different concentrations of Co (10 % and 15 %) were evaluated through three electrode assemblies. It is significant to note that although Co smoothed the surface of NiVO, most of the nickel vanadate crystals broke apart into tiny particles and increased the number of electroactive sites. Pure NiVO has a specific capacitance (Cs) of 1638.06 F/g at 5 mV/s. It has been observed that the electrochemical performance has been improved by adding Co 10 % and 15 % in NiVO. The 15 % Co-doped NiVO exhibits an outstanding Cs of 2641.99 F/g at a scan rate of 5 mV/s with a high capacitance retention of 98.14 % after 1k charge-discharges cycles. This excellent performance of the material is due to more electroactive sites and synergistic effects among Co and Ni in the composite. To further elaborate the electrochemical performance of 15 % Co-doped NiVO, it is employed for the fabrication of a symmetries supercapacitor (SSC) device, which shows that the fabricated device has a capacitance of 286 F/g at a current density (CD) of 0.5 A/g and high energy density of 39.7 Wh/kg at a power density of 333.33 W/kg. The symmetric device maintains a cyclic stability of 93.8 % while undergoing 5000 consecutive charge–discharge cycles at a current density of 10 A/g. Based on rigorous testing and analysis, these findings suggest that the prepared electrode material is reliable and suitable for implementation in forthcoming wearable electronic systems.

Dual carbon confining SnO2 nanocrystals as high-performance anode for sodium-ion batteries

The increasing global demand for sustainable energy sources has driven research into sodium-ion batteries (SIBs) for large-scale energy storage. However, their electrochemical performance is hindered by poor reaction kinetics and significant volume expansion in electrode materials. In this work, we developed a dual-carbon-confined SnO2 nanocrystal anode (CNTs@SnO2@NC) designed for high-performance SIBs. This innovative structure uses carbon nanotubes (CNTs) and a nitrogen-doped carbon (NC) coating to stabilize SnO2, ensuring structural integrity during charge/discharge cycles. The CNTs network in CNTs@SnO2@NC can alleviate the agglomeration of SnO2 nanocrystals to a certain extent; With its superior electronic conductivity, CNTs can enhance the anode's conductivity and function as an electronic highway; The sodiophilic properties and good electrical conductivity of CNTs enable sodium ions to migrate rapidly on the surface of the nanotubes. Moreover, numerous external defects and active sites generated by nitrogen doping enhance the sodium ion absorption capabilities; The existence of nitrogen-doped carbon coating can effectively accommodate the volume changes of SnO2 and enhance the structural stability of CNTs@SnO2@NC composites during the repeated charge and discharge cycles. As a result, the CNTs@SnO2@NC composite demonstrates excellent electrochemical performance, achieving capacity of 235 mAh g−1 at 0.1 A g−1 over 100 cycles and 102 mAh g−1 at 1.0 A g−1 over 300 cycles. In a full-cell configuration with a Na3V2(PO4)3 cathode, it delivers 38 mAh g−1 at 100th cycle at 0.1 A g−1. This study underscores the substantial improvements achieved by dual-carbon confinement for high-performance SIB anodes, offering a promising direction for future anode material design.

Entropy-Modulated Short-Chain Cathode for Low-Temperature All-Solid-State Li-S Batteries.

All-solid-state Li-S batteries (ASSLSBs) due to high theoretical energy density and exceptional safety are highly desirable for electric aircraft. However, as the flight altitude rises, the low-temperature performance is hampered by inadequate practical capacity. Here, we discover that low-temperature sulfur utilization is constrained by the multi-step endothermic conversion reaction. By introducing multi-chalcogen to modulate the local entropy, a short-chain molecule cathode is designed to shorten the reduction pathways and enhance low-temperature discharge capacity. Furthermore, the mismatched lithiation lattice of the short-chain cathode reduces the decomposition energy barriers, thus enhancing low-temperature charge/discharge reversibility. The designed short-chain cathode exhibits high cathode utilization (99.4%) and cycling stability (400 cycles, 92.2% retention) at room temperature, as well as delivers excellent discharge capacity (579.6 mAh g-1, -40 °C) and cycling performance (100 cycles, 98.4% retention, 394.9 Wh kg-1electrode, -20 °C) at low temperature. This study presents new opportunities to stimulate the development of low-temperature ASSLSBs.

A Fluorinated Lewis Acidic Organoboron Tunes Polysulfide Complex Structure for High‐Performance Lithium–Sulfur Batteries

AbstractMany challenges in lithium‐sulfur (Li–S) batteries are associated with the radical change in lithium polysulfide (LPS) solubility during cycling, but chemical approaches to address such inconsistency are still lacking. Here, the use of a strong Lewis acidic fluorinated organoboron, tri(2,2,2‐trifluoroethyl) borate (TFEB), is reported as a multi‐functional mediator to simultaneously overcome multiple technical barriers in practical Li–S batteries. TFEB acts as an anion acceptor and forms strong molecular complexes with Lewis basic LPS. The TFEB‐LPS complexes have consistent solubility across the full polysulfide spectrum and deliver several times improved better redox kinetics, unlocking a true redox catalytic mechanism that covers the majority of redox events in thick sulfur cathodes. As a result, Li–S batteries evaluated under practical conditions exhibit significantly improved discharge capacity, rate capability, and cycling stability with the addition of the TFEB additive. More importantly, TFEB also contributes to the stabilization of lithium anode in the presence of polysulfides by generating strong interfacial film. These attributes significantly improve the cycling stability of practical Li–S pouch cells, which are assembled with a unit energy density of 219 Wh kg−1. The results provide new molecular insights on the design of unlocking solvation networks of practical Li–S systems.

Rational modulation of fluorophosphate cathode by anionic groups to reduce the polarization behavior for fast-charging sodium-ion batteries

Na3V2(PO4)2O2F (VP) is recognized as a promising cathode material for sodium-ion batteries due to its stable structural framework and high specific capacity. Density functional theory (DFT) and finite element simulations show that incorporating SO42− into VP decreases its band gap, lowers the migration energy barrier, and ensures a uniform Na+ concentration gradient and stress distribution during charge and discharge cycles. Consequently, the average Na+ diffusion coefficient of Na3V2(PO4)1.95(SO4)0.05O2F (VPS-1) is roughly double that of VP, leading to enhanced rate capability (80 C, 75.5 mAh g−1) and cycling stability (111.0 mAh g−1 capacity after 1000 cycles at 10 C current density) for VPS-1. VPS-1 exhibits outstanding fast-charging capabilities, achieving an 80% state of charge in just 8.1 min. The assembled VPS-1//SbSn/NPC full cell demonstrated stable cycling over 200 cycles at a high 5 C current, maintaining an average coulombic efficiency of 95.35%.

Novel binder-free vanadium-based molten salt (NMPV) with low-cost as anode materials of lithium-ion batteries

Molten salt NMPV material is synthesised using a one-step method and applied to binder-free anodes for lithium-ion batteries (LIBs). In this work, simple, low-cost and highly active coordination molten salt electrode materials (NMPV and NMPV-C) were prepared, which overcame the drawbacks of cumbersome and costly preparation of the existing electrode materials. NMPV is formed by the lone pair of electrons of N-methyl pyrrolidone (NMP) molecules coordinated with vanadium ion. The synergistic effect produced by these two and the excellent electrical conductivity and electrochemical properties of the molten salt material itself exhibits satisfactory lithium storage results. The discharge capacities of NMPV-C and NMPV in the second discharge cycle are 669 and 345 mAh g−1, respectively. After 100 cycles, the capacity is maintained at 923 and 549 mAh g−1, respectively. And the capacity retention is 137.97 % and 159.13 %, respectively. In addition, the NMPV-C electrode maintains a stable reversible capacity of 450 mAh g−1 at 2000 mAh g−1 after 220 cycles. Density-functional theory (DFT) calculations revealed that Li+ is more likely to attack H on methyl nitrogen, which is the optimal reaction site for NMPV since the lone pair of electrons of N effectively stabilises the carbon cation after the reaction of Li with H.

Application of Deep Learning Techniques for the State of Charge Prediction of Lithium-Ion Batteries

This study proposes a deep learning-based long short-term memory (LSTM) model to predict the state of charge (SOC) of lithium-ion batteries. The purpose of the research is to accurately model the complex nonlinear behavior that occurs during the charging and discharging processes of batteries to predict the SOC. The LSTM model was trained using battery data collected under various temperature and load conditions. To evaluate the performance of the artificial intelligence model, measurement data from the CS2 lithium-ion battery provided by the University of Maryland College of Engineering was utilized. The LSTM model excels in learning long-term dependencies from sequence data, effectively modeling temporal patterns in battery data. The study trained the LSTM model based on battery data collected from various charge and discharge cycles and evaluated the model’s performance by epoch to determine the optimal configuration. The proposed model demonstrated high SOC estimation accuracy for various charging and discharging profiles. As training progressed, the model’s predictive performance improved, with the predicted SOC moving from 14.8400% at epoch 10 to 12.4968% at epoch 60, approaching the actual SOC value of 13.5441%. Simultaneously, the mean absolute error (MAE) and root mean squared error (RMSE) decreased from 0.9185% and 1.3009% at epoch 10 to 0.2333% and 0.5682% at epoch 60, respectively, indicating continuous improvement in predictive performance. In conclusion, this study demonstrates the effectiveness of the LSTM model for predicting the SOC of lithium-ion batteries and its potential to enhance the performance of battery management systems.

Synthesis of Eco-friendly Zn-Ni bimetallic MOFs with biodegradable glycolic acid ligands for enhanced supercapacitor performance and hydrogen evolution reaction

Electrochemical technologies like supercapacitors and water-splitting electrolysis are gaining traction due to their impressive efficiency in both energy storage and generation. A hydrothermal technique was employed to synthesize a metal–organic framework (MOF) containing zinc and nickel. Glycolic acid (GA), a naturally occurring biodegradable ligand, was utilized to explore its potential for incorporation into the MOF heterostructure. The ZnNi-MOF (GA) composites showed a notable specific capacity of 1648 C g−1 (2060 F/g) under a current density of 1.0 A g−1 at 70 °C. The study investigated a supercapacitor system design where a combination of polyaniline-doped activated carbon was used for the negative electrode and a zinc-nickel metal–organic framework (GA) was used for the positive electrode. The synthesized ZnNi-MOF (GA)//AC energy storage device demonstrated a specific capacity of 110 C g−1 (55 F g−1) at a higher current density of 2.0 A g−1. The recyclability and stability of device (ZnNi-MOF (GA)//AC) were evaluated using 10000 charge–discharge cycles, yielding an 86% capacity retention. The ZnNi-MOF (GA) composite displayed outstanding catalytic ability in the hydrogen evolution reaction (HER) in comparison to other tested materials, achieving the lowest Tafel slope of 42.79 mV/dec. The findings of our research suggest that ZnNi-MOF (GA) exhibits desirable characteristics that make it a promising material for electrodes in the applications of supercapattery and HER.

Ultra-small one-dimensional rice-like CoMoO4 nanorods as a promising pseudocapacitive electrode for high-performance supercapacitors

The demand for sustainable energy sources increases as society progresses. Supercapacitors possess a long lifespan, have a high power density, are ecologically sound, and have the ability to rapidly charge and discharge. Among the several binary transition metal oxides (BTMOs), metal molybdates (AMoO4) are notable for their significant redox activity, widespread availability, affordability, and small ecological footprint. The exceptional theoretical capacitance of CoMoO4, resulting from the presence of active cobalt ions, distinguishes it from other materials. However, the synthesis of CoMoO4 in nanostructured forms presents a challenge. This study introduces a straightforward one-pot solvothermal technique for producing ultra-small, one-dimensional (1D) rice-like CoMoO4 nanorods. The electrochemical performance of rice-like CoMoO4 nanorods as a supercapacitor electrode material was thoroughly investigated, along with larger CoMoO4 nanorods made using the hydrothermal process for comparison. The structural, morphological, and surface characteristics of the rice-like CoMoO4 nanorods were comprehensively examined. The nanorods, formed like rice grains, exhibited exceptional ability to store electric charge, with an outstanding specific capacitance of 1608.8 F g−1. They demonstrated remarkable cycling stability, retaining 96 % of their capacitance after numerous charge and discharge cycles, indicating their durability and reliability. The nanorods also exhibited a high rate capability of 71 %, which is crucial for applications that demand quick energy delivery. This capability enables the nanorods to maintain considerable capacitance even at higher charge-discharge rates. The results indicate that rice-like CoMoO4 nanorods can be used as a material in supercapacitors.

TPDH-Graphene as a New Anodic Material for Lithium Ion Battery: DFT-Based Investigations.

The potential of tetra-penta-deca-hexagonal graphene (TPDH-gr), a recently proposed 2D carbon allotrope as an anodic material in lithium ion batteries (LIBs), was investigated through density functional theory calculations. The results indicate that Li-atom adsorption is moderate (around 0.70 eV), allowing for easy desorption. Moreover, energy barriers (0.08-0.20 eV), diffusion coefficient (>6 × 10-6 cm2/s), and open circuit voltage (0.29 V) calculations show rapid Li atom diffusion on the TPDH-gr surface, stable intercalation of lithium atoms, and good performance during the charge and discharge cycles of the LIB. These findings, combined with the intrinsic metallic nature of TPDH-gr, indicate that this new 2D carbon allotrope is a promising candidate for use as an anodic LIB material.

Waste Bakelite Board Derived Activated Carbon for Supercapacitor Electrode

The low biodegradability of Bakelite waste raises concerns for the environment as it is typically dumped in landfills. Herein we present regenerated activated carbon (AC) prepared from waste Bakelite board. Preparation of the ACs involves carbonization and KOH activation. Afterwards, the as-made AC were doped with N urea and subsequently pyrolyzed at high temperature. The resulting AC, with and without N-doping have been evaluated in supercapacitor. We demonstrate an N-doped AC that exhibits a specific capacitance (Csp) as high as 203.0 F g−1 at 0.5 A g−1 and retains 93.1% of the Csp after 5000 galvanostatic charge discharge (GCD) cycles at 3 A g−1. We also show that a symmetric supercapacitor exhibits a maximum energy density of 10.3 Wh kg−1 at 250 W kg−1. In general, our work shows a cost-effective approach towards high-performance waste-regenerated ACs.

Inkjet-printed flexible V2CTx film electrodes with excellent photoelectric properties and high capacities for energy storage device

Energy storage devices are progressively advancing in the light-weight, flexible, and wearable direction. Ti3C2Tx flexible film electrodes fabricated via a non-contact, cost-effective, high-efficiency, and large-scale inkjet printing technology were capable of satisfying these demands in our previous report. However, other MXenes that can be employed in flexible energy storage devices remain undiscovered. Herein, flexible V2CTx film electrodes (with the low formula weight vs Ti3C2Tx film electrodes) with both high capacities and excellent photoelectric properties were first fabricated. The area capacitances of V2CTx film electrodes reached 531.3–5787.0 μF⋅cm−2 at 5 mV⋅s−1, corresponding to the figure of merits (FoMs) of 0.07–0.15. Noteworthy, V2CTx film electrode exhibited excellent cyclic stability with the capacitance retention of 83 % after 7,000 consecutive charge–discharge cycles. Furthermore, flexible all solid-state symmetric V2CTx supercapacitor was assembled with the area capacitance of 23.4 μF⋅cm−2 at 5 mV⋅s−1. Inkjet printing technology reaches the combination of excellent photoelectric properties and high capacities of flexible V2CTx film electrodes, which provides a new strategy for manufacturing MXene film electrodes, broadening the application prospect of flexible energy storage devices.

The design of binder-free self-supporting carbon paper electrode based on biomass derived hierarchical porous carbon/cellulose nanofibers for sustainable flexible supercapacitors

The design and synthesis of advanced electrodes with high conductivity and flexibility are the key to the development of wearable energy storage devices. Herein, a strategy for preparing conductive carbon paper electrode for flexible supercapacitors is reported by vacuum filtration of a mixture of biomass hierarchical porous carbon materials (HPC), cellulose nanofibers (CNFs) from polysaccharide cellulose of plant origin and silver nanowire (AgNWs), in which CNFs serve as substrates for dispersion and crosslinking of HPC. The prepared self-supporting electrode showed multi-scale pore structure and excellent conductivity (14.1 S cm−1). The electrode exhibited the highest specific capacitance of 383 F g−1 at 0.5 A g−1. Even after 10,000 charge and discharge cycles, 95 % of the original capacitance was remained, which means excellent cyclic stability. High strength and flexibility of the as-assembled flexible supercapacitor make the electrochemical performance of this device remain unchanged when bent at any angle. The present research delineates a simple and convenient method to prepare green, efficient and low-cost flexible supercapacitor.

Preparation of MnS/NiCo2S4 composite nanosheets self-supported electrode and the performance in water-system asymmetric supercapacitors

Abstract In this paper, the MnS@NiCo2S4 composite self-supporting electrode was designed and prepared with a mixture of nickel, cobalt, and manganese sulfide as the research object. The capacitance of the electrode can reach 2, 372.7 F g−1 at the current density of 1 A g−1, and the voltage window can also be widened to 0-0.6 V and maintains a multiplier performance of 62.1% at 10 A g−1. Following 5, 000 cycles of charging and discharging, the electrode exhibits a capacity retention of 78.2% relative to its initial capacity, with the coulombic efficiency consistently hovering around 100%. This performance indicates that the electrode can carry out stable and reversible electrochemical processes. A supercapacitor assembled with 1 M KOH as the electrolyte, activated carbon as the anode, and MnS/NiCo2S4 as the cathode, delivers an energy density of 46.9 W h kg−1. In the life test of the charge and discharge cycle, the discharge capacity after 10, 000 cycles is 89.2% of the initial capacity, indicating that the device has good cycle stability. This study provides an idea for the potential application of metal sulfide-based electrodes with wide potential windows and high electrochemical properties in water asymmetric supercapacitors.

Study of two thermally integrated pumped thermal electricity storage systems using distinct working fluid groups: Performance comparison

As a competitive new energy storage technology, the thermally integrated pumped thermal electricity storage (TI-PTES) system has received much attention. In this work, two TI-PTES systems are constructed: the RHP-BORC system, which consists of a heat pump cycle (HP) with a regenerator and a basic organic Rankine cycle (BORC), and the RHP-EOFC system, which consists of a HP with a regenerator and an organic flash cycle with ejectors. Meanwhile, R1233zd(E) and Cis-butene are selected to form R1233zd(E)/R1233zd(E) (denoting the working fluid used in the charge and discharge cycles, respectively), R1233zd(E)/Cis-butene, Cis-butene/Cis-butene, and Cis-butene/R1233zd(E) groups. Thermodynamic and economic analyses as well as multi-objective optimization are performed for both systems. The results indicate that for the two systems with different working fluid groups, different parameters have distinct effects on the system performance, and the thermodynamic and economic performance of the RHP-BORC system is better than those of the RHP-EOFC system. For the RHP-BORC system, with the variations of thermal storage temperature, evaporation temperature of heat pump and pinch point temperature difference, the values of different performance metrics of the system with different working fluid groups are close respectively, such as power-to-power efficiency, energy storage density and annual emission reduction. For the RHP-EOFC system under different parameter conditions, when the system uses R1233zd(E)/Cis-butene and Cis-butene/Cis-butene, the performance is better. From the results of the multi-objective optimization, the optimal working fluid group of the RHP-BORC and RHP-EOFC systems are Cis-butene/Cis-butene and R1233zd(E)/Cis-butene, and the values of the power-to-power efficiency and the levelized cost of storage under the optimal solution conditions are 75.76 %, 0.234 $·kWh−1, and 84.31 %, 0.227 $·kWh−1, respectively. The results of the exergy destruction analysis under the optimal solution conditions show that the largest exergy destruction in the RHP-BORC and RHP-EOFC systems are in the condenser (480 kW) and compressor (1275 kW) of the HP cycle. This work expands the configuration of the TI-PTES system, showing promising development prospects. It also provides theoretical support for the further advancement of the TI-PTES system and offers valuable guidance for the design of such systems.