Cathode For Rechargeable Batteries Research Articles

Advanced K3V2(PO4)2O2F cathode for rechargeable potassium-ion batteries with high energy density

Potassium-ion batteries (PIBs) have emerged as promising candidates for cost-effective and sustainable energy-storage systems. Nevertheless, limited by the large K+ radius, PIBs have great difficulty in figuring out and designing suitable host materials. Herein, a suitable cathode material K3V2(PO4)2O2F (KVPOF) for PIBs has been carefully prepared. It exhibits a high specific capacity close to the theoretical value, 116.3 mAh/g at 20 mA/g within the voltage window of 2.0–4.5 V vs K+/K, corresponding to a de-/intercalation process of ∼2 mol K+ per formula unit. In addition, it presents an average operating voltage plateau of about 3.5 V, resulting in an energy density of about 410 Wh/kg. The crystal structure and phase transition are revealed by in situ x-ray diffraction, and the structure is found to be fully reversible during the de-/intercalation of K+. Furthermore, the potential of KVPOF cathode for applications at low temperatures was explored, and the full cell matched with graphite anode demonstrated fair electrochemical performance. The experimental results suggest the feasibility of using KVPOF as cathode material for rechargeable PIBs.

A New Cathode for Rechargeable Magnesium Batteries

A New Cathode for Rechargeable Magnesium Batteries

Utilization of Delithiation-Induced Amorphous Oxide as a Cathode for Rechargeable Magnesium Batteries

Utilization of Delithiation-Induced Amorphous Oxide as a Cathode for Rechargeable Magnesium Batteries

Advanced Prussian Blue Cathodes for Rechargeable Li-Ion Batteries

Taking advantage of fact that the surface electrons of metallic nanoparticles (NPs) can be effectively released even at a low voltage bias, we demonstrate an improvement in the electrochemical performance of nanosized Prussian Blue (PB)-based secondary batteries through the incorporation of bare Ag or Ni NPs in the vicinity of the working PB NPs. It is found that the capacity for electrochemical energy storage of the 17 nm PB-based battery is significantly higher than the capacity of 10 nm PB-based, 35 nm PB-based or 46 nm PB-based batteries. There is a critical PB size for the highest electrochemical energy storage efficiency. The full specific capacity CF of the 17 nm PB-based battery stabilized to 62 mAh/g after 130 charge–discharge cycles at a working current of IW = 0.03 mA. The addition of 14 mass percent of Ag NPs in the vicinity of the PB NPs gave rise to a 32% increase in the stabilized CF. A 42% increase in the stabilized CF could be obtained with the addition of 14 mass percent of Ag NPs on the working electrode of the 35 nm PB-based battery. An enhancement in CF was also found for electrodes incorporating bare Ni NPs but the effect was smaller.

Electrode Behavior of Exfoliated Graphite Cathode for Aluminum Metal Anode Rechargeable Battery

Electrode Behavior of Exfoliated Graphite Cathode for Aluminum Metal Anode Rechargeable Battery

Poly(3-Methylthiophene)/Graphene Composite Cathode for Rechargeable Aluminum-Ion Batteries.

To reduce the dependence on traditional fossil energy, developing efficient energy storage systems is urgent. The reserves of aluminum resources in the earth's crust are extremely rich, which makes aluminum-ion batteries a promising competitor of new energy storage devices. Here, we report a poly(3-methylthiophene)/graphene (P3TH/Graphene) composite as the cathode of an aluminum-ion battery. The adjustment of polymer chain spacing by the methyl side chain provides a channel conducive to the transport of large-size AlCl4- complexes. The addition of electron donor groups also changes the electron delocalization characteristics of polymers and improves the specific capacity of the material. At the same time, the in situ composite of graphene can enhance the Π-Π interaction to form a favorable electronic transmission channel. At a current density of 200 mA g-1, the P3TH/Graphene composite showed a specific capacity of ∼150 mA g-1. The flexible structure of the polymer also guarantees the excellent rate capability of the composite.

A stepwise thermal migration for inducing copper nanoparticles to boost oxygen reduction activity of single-atomic copper sites

Although single-atom M-N-C electrocatalysts have demonstrated their potential in metal-air batteries and fuel cells, their activity for oxygen reduction reaction (ORR) needs to be further improved. Regulating the electronic structure of M-Nx single sites to accelerate the activity and simultaneously directly identify the enhancement mechanisms is highly desirable but remains a challenge. Here we propose a stepwise thermal migration strategy to in situ introducing Cu nanoparticles (Cu-NPs) adjacent to single atoms Cu (Cu-SAs) confined into hierarchically porous carbon. The optimization of the electronic structure of the Cu-Nx site by adjacent Cu nanoparticles is confirmed by both enhanced ORR activity and theoretical calculations. The optimized CuSA-NP@NC exhibits a more positive half-wave potential (0.870 V) than CuSA@NC (0.842 V) and superior stability with an 86.6% ORR current retention after 24 hours of chronoamperometric test in alkaline electrolyte. When utilized as an air cathode in rechargeable Zn-air batteries, CuSA-NP@NC displays a high-power density of 224.1 mWcm−2 and a specific capacity of 802.0 mAh g−1. Theoretical calculations demonstrate that the introduction of Cu-NPs endows the Cu-N4 site with an enriched electron density, which optimizes the adsorption/desorption of ORR intermediates on the Cu-N4 sites. This work reports an effective way and provides insights into the ORR activity improvement of single-atom electrocatalysts.

Mo3S13 Cluster-Based Cathodes for Rechargeable Magnesium Batteries: Reversible Magnesium Association/Dissociation at the Bridging Disulfur along with Sulfur–Sulfur Bond Break/Formation

Mo₃S₁₃ Cluster-Based Cathodes for Rechargeable Magnesium Batteries: Reversible Magnesium Association/Dissociation at the Bridging Disulfur along with Sulfur–Sulfur Bond Break/Formation

Co/Co3O4 Heterojunctions Encased in Porous N-Doped Carbon Nanocapsules for High-Performance Cathode of Rechargeable Zinc-Air Batteries.

A long-term goal of rechargeable zinc-air batteries (ZABs) has always been to design bifunctional electrocatalysts that are robust, effective, and affordable for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). It has become a feasible method to construct metal/metal oxide interfaces to achieve superior electrocatalytic performance for ORR and OER by enhanced charge transfer. In this study, Co/Co3O4 heterojunctions were successfully prepared and encased in porous N-doped mesoporous carbon (Co/Co3O4@NC) via a simple condensation-carbonization-etching method. The extensive specific surface area of Co/Co3O4@NC facilitates effective interaction between the electrolyte and the catalyst, thereby enabling sufficient exposure of active sites for the ORR and the OER, consequently enhancing the rate of transport of active species. The well-designed Co/Co3O4@NC delivers superior ORR catalytic activity with a half-wave potential of 0.82 V (vs RHE) and a low overpotential of 347 mV at 10 mA cm-2 for OER in alkaline solution. The power density of Co/Co3O4@NC-based alkaline aqueous ZAB (156.5 mW cm-2) is superior to the commercial Pt/C + IrO2-based alkaline aqueous ZAB, and the cycling stability of ZAB is up to 220 h. In addition, Co/Co3O4@NC-based ZAB shows a high power density (50.1 mW cm-2). The construction of metal/metal oxide heterojunction encased in N-doped mesoporous carbon provides a novel route for the design of bifunctional electrocatalysts for high-performance ZABs.

The tellurium-induced CoSe polyhedral porous nano-structured materials as high-performance cathodes for rechargeable magnesium batteries

Rechargeable magnesium batteries (RMBs) are cost-effective and dendrite-free, making them desirable for large-scale applications. Nevertheless, the exploration of high-performance cathodes still remains a great challenge in magnesium battery research. Herein, the CoSe porous polyhedra induced by Te heteroatoms (CoSe/Te) are successfully prepared by two-step metal-organic framework (MOF)-template assisted method and investigated as high-efficiency cathodes for rechargeable MIBs. In this regard, the affluent porous structure can facilitate the transport of Mg2+ ions while the introduction of Te heteroatoms can reduce the conversion reaction barrier, boost the kinetics and redox reversibility and excite the electron conduction to build active nanostructured domains for highly reversible Mg storage reactions. As a consequence, the CoSe/Te maintains the high specific capacity of 150.6 mAh g−1 after 600 cycles at 200 mA g−1, with a superior capacity retention rate of 75.3%. Moreover, the specific capacity of such electrode materials changed from 260 mAh g−1 to 41 mAh g−1 when the current density increased from 100 mA g−1 to 2000 mA g−1, and gradually recovered to 256.5 mAh g−1 when the current density returned to 100 mAh g−1, exhibiting a better rate performance. This work highlights how micro-nanostructures can favor magnesium storage reaction reversibility and cyclability and also provide insights into rational electrode design for storing magnesium cations in future studies.

Competition between dual alkali metal ions fuels high-performance sodium-ion batteries

Dual alkali metal ion battery is expected to apply in future high-efficiency energy storage applications as it can skillfully combine the advantages of Li+ and Na+. However, the specific insertion and extraction processes of the two ions are not well explained. Herein, a layered sodium transition metal oxide electrode with ordered mixing of Na/Li ions is prepared by ion exchange method. The ion behavior is explained in terms of activation energy of chemical reaction and Gibbs free energy. Based on thermodynamic analysis and material characterizations, the priorities of Na+ and Li+ deblock reactions are determined. The competition mechanism of alkali metal ions and the double gain effect of Li are revealed by electrochemical experiments. This work is expected to provide a positive impact on the future design of multifunctional cathodes for advanced rechargeable batteries.

Copper selenide/amino hyperbranched polymer as an organic/inorganic hybrid composite cathode for rechargeable magnesium batteries

An organic/inorganic hybrid cathode is used for rechargeable magnesium batteries. Large interphase favors charge transfer, coordination of Cu2+ by the polymer enhances cyclability, and elastic matrix buffers volume change of conversion reaction.

Manganese–carbon (Mn–C) interaction to host Al3+-ions in a β-MnO2–MWCNT composite cathode in rechargeable aluminium ion batteries

Rechargeable Aluminium Ion Batteries (AIBs) are one of the potential metal battery alternatives to Li-ion batteries.

Design of a light-sensitive tubular MoS2/C composite as the cathode for photo-enhanced rechargeable zinc-ion batteries

Utilizing solar energy to charge electrical energy storage devices has currently emerged as a hot and promising research direction to replace the traditional charging processes.

Securing cation vacancies to enable reversible Mg insertion/extraction in rocksalt oxides

Introducing and securing cation vacancies in a crystalline structure activates the disordered rocksalt oxide cathodes for rechargeable magnesium batteries. This strategy provides a new opportunity for novel cathode materials.

Monitoring Copper Ion Leaching from a Metalloporphyrin-Based Cathode for Rechargeable Magnesium Batteries

Great efforts are being undertaken to characterize the fundamental processes of solid electrolyte interphase (SEI) formation, degradation, and initial conditioning steps of battery electrode materials, including organic electrode materials.[1] Imaging techniques, such as focused ion beam / scanning electron microscopy (FIB/SEM) tomography in combination with element mapping using energy- and wavelength-dispersive X-ray spectroscopy are employed to gain insight into distribution, interconnectivity, and porosity of active materials as well as electrolyte penetration and their influence on degradation processes after longer cycling times.[2] Additionally, electrochemical impedance spectroscopy[3] and anodic stripping voltammetry[4] are used to shed light on those processes. The metalloporphyrin-based material [5,15-bis(ethynyl)-10,20-diphenylporphinato]copper(II) (CuDEPP) has been used as an interesting material for cathodes and anodes of various battery chemistries. These materials undergo initial self-conditioning by electro-polymerization for monovalent ions. With respect to multivalent ions, like magnesium, this polymerization is far less pronounced and an exchange of the copper from the CuDEPP by magnesium ions appears to be occurring.[5] Gaining insight into this trans- or demetallation process induced by parameters like the electrochemical driving force during galvanostatic cycling is a complex analytical challenge.We report the use of Hg ultramicroelectrodes and anodic stripping voltammetry as a sensitive strategy to detect copper ion leaching from metalloporphyrin-based CuDEPP composite electrodes. We demonstrate in-situ/intermittent monitoring of copper ion release during the initial self-conditioning step of the active material while galvanostatic cycling of the battery electrode in dimethoxy ethane. This method could be used to assess the release of an ionic species from complex systems, like composite battery electrodes.

Synthesis, Electrochemical Properties and Crystal and Electronic Structure Changes in Charge/Discharge Process of Spinel Type Cathode-Materials Mg1.33-Y(V1.67-x+yMnx)O4 for Magnesium Secondary Batteries

Attention has therefore focused on rechargeable batteries using multivalent cations, which are expected to offer even higher energy densities than lithium ion batteries. One topic that has attracted attention is rechargeable batteries using Mg as a carrier. The advantage of using Mg is that it has a low electrode potential with a high capacity.Although previous research into Mg rechargeable battery cathode materials started with a report by Aurbach1) et al., and included chevrel compounds, these have had problems in terms of battery voltage and cycle properties. In spinel-type Mg1+yCo2-x-yMnxO4, charge and discharge capacities were reported to increase by substituting Mn2). V is thought to have high reversibility due to having a broad mixed atomic valence. The authors synthesized Mg1.33V1.57Ni0.1O4, and reported that the discharge capacity after 14 cycles was 160 mAh/g and the capacity retention rate was high3). Furthermore, the authors investigated the spinel solid solution αMgCo1.5Mn0.5O4-(1-α)Mg(Mg0.33V1.57Ni0.1)O4 as a new cathode material and evaluated its battery properties, and as a result found that the initial discharge capacity at α = 0.3 was 180 mAh/g with the discharge capacity maintained after 60 cycles4 ). However, the substitution products need to be investigated in order to improve the discharge potential of the Mg-V system and enhance the cycle properties.The present study investigated the synthesis of a new spinel type cathode material Mg1.33-y(V1.67-x+yMnx)O4 by substituting Mn into Mg1.33V1.67O4 and different Mg content in order to increase the charge-discharge capacity and improve the cycle properties. The crystal and electronic structures and charge-discharge properties depending on the amount of Mn substitution and Mg content, and the structural changes accompanying charging and discharging.Mg1.33-y(V1.67-x+yMnx)O4 was synthesized by a solid -phase method under high vacuum atmosphere. The product was assigned to the spinel structure with space group Fd-3m from the powder X-ray diffraction. Synthesized materials of uniform composition were confirmed from elemental mapping by STEM-EDS. Charge and discharge cycle tests showed that the deliverable discharge capacity depends on the cycle number, Mn composition, and working temperature. The charge and discharge cycle tests showed the discharge capacity increased with repeated cycles. Mg1.33V1.57Mn0.1O4 showed the largest discharge capacity of 256 mAh/g at 13th cycles while the initial capacity was only 73 mAh/g at 90°C. The local structure was analyzed based on EXAFS spectra at the V K-edge for the pristine and electrode materials, and the results suggested that Mg1.33V1.57Mn0.1O4 had the smallest lattice distortion due to Mn at 16d sites, and XAFS spectra at the V K-edge indicated the significant change in the oxidation state of V during the charge/discharge cycles. The particularly stable crystal structure and large contribution of charge compensation by V may jointly contribute to the superior charge-discharge property of Mg1.33V1.57Mn0.1O4 5).Moreover, we investigated the different Mg, Mn content sample. Mg1.25(V1.55Mn0.2)O4 showed an increase in capacity from the first discharge capacity 71mAh/g to 199mAh/g after 34 cycles at 90℃ (Fig.1). The change in crystal structure due to charging and discharging was investigated. Focusing on the magnitude of M(16d)-O6 octahedral strain, the strain after 10th discharge is significantly reduced, so it is considered that the structure was stabilized by repeating the cycles and contributed to the improvement of the cycles characteristics. The electronic structure was analyzed by MEM, which showed that the electron density between the 16d-32e sites was higher and the covalent bond was higher than that of the diffusion sites after charge and discharge. From this, it is considered that the host structure was stabilized by charge and discharge, which contributed to the increase in charge and discharge capacity. From the result of XANES, it revealed that V is trivalent to tetravalent and Mn is divalent. Furthermore, from the results of EXAFS, it was clarified that the amount of reduction was larger in Mg1.25(V1.55Mn0.2)O4, especially in charge and discharge, because the amount of change in the distance between V and O was larger. Acknowledgements This work was supported by JST ALCA-SPRING Grant Number JPMJAC1301, Japan.We are deeply grateful for the cooperation of Dr. T. Honma and Dr. H. Ofuchi of JASRI for the XAFS analyses (SPring-8, BL14B2), Dr. K. Osaka of JASRI for the measurement of the synchrotron X-ray diffraction (SPring-8, BL19B2). References 1) D. Aurbach, et al., Adv. Mater., 19, 4260 (2007).2) Y. Idemoto, et al., J. Power Sources, 482, 228920 (2021).3) Y. Idemoto, et al., J. Power Sources, 455, 227962 (2020).4) Y. Idemoto, et al, Electrochemistry, 90(2), 027002(2022).5) Y. Idemoto, et al, J. Electroanal. Chem., 928, 1107064 (2023). Figure 1

Engineering Low‐Cost Organic Cathode for Aqueous Rechargeable Battery and Demonstrating the Proton Intercalation Mechanism for Pyrazine Energy Storage Unit

AbstractSeeking organic cathode materials with low cost and long cycle life that can be employed for large‐scale energy storage remains a significant challenge. This work has synthesized an organic compound, triphenazino[2,3‐b](1,4,5,8,9,12‐hexaazatriphenylene) (TPHATP), with as high as 87.16% yield. This compound has a highly π‐conjugated and rigid molecular structure, which is synthesized by capping hexaketocyclohexane with three molecules of 2,3‐diaminophenazine derived from low‐cost o‐phenylenediamine, and is used as a cathode material for assembling aqueous rechargeable zinc ion batteries. Both experiments and DFT calculations demonstrate that the redox mechanism of TPHATP is predominantly governed by H+ storage. The Zn‐intercalation product of nitride‐type compound, is too unstable to form in water. Moreover, the TPHATP cathode exhibits a capacity of as high as 318.3 mAh g−1 at 0.1 A g−1, and maintained a stable capacity of 111.9 mAh g−1 at a large current density of 10 A g−1 for 5000 cycles with only a decay of 0.000512% per cycle. This study provides new insights into understanding pyrazine as an active redox group and offers a potential affordable aqueous battery system for grid‐scale energy storage.

Superior electronic/ionic kinetics of LiMn0.8Fe0.2PO4@C nanoparticles cathode by doping strategy toward enhanced Li-ion storage

The practical applications of LiMn0.8Fe0.2PO4 have been greatly limited due to its low electrical conductivity and inferior electrochemical reaction kinetics. Herein, a Ni-doped strategy has been employed to optimize the morphology of LiMn0.8Fe0.2PO4 nanoparticles with preferred growth orientation, leads to improved electrical/ionic conductivity and electrode kinetic. Compared with pristine sample (Ni-D0), the electrical conductivity, ion diffusion coefficient and exchange current density of 5 mol% Ni-doped sample (Ni-D5) are obviously increased to 9.57 × 10−2 S cm−1, 3.301 × 10−11 cm2 s−1, and 0.339 mA cm−2, respectively. The first principle calculations also confirmed the enhanced electrical conductivity of LiMn0.8Fe0.15Ni0.05PO4@C. Meanwhile, Ni-D5 exhibits good rate capability and cycling stability. Furthermore, the operando XRD analysis demonstrated its highly structural stability and reversible properties. Therefore, the Ni-doped strategy is considered a promising and effective modification approach to enhance the Li-storage capability of LiMn0.8Fe0.2PO4 cathode for high performance rechargeable second batteries.

Hypercrosslinked Phenothiazine Polymer as a Low-Cost and Durable Organic Cathode for Rechargeable Lithium Batteries

Hypercrosslinked Phenothiazine Polymer as a Low-Cost and Durable Organic Cathode for Rechargeable Lithium Batteries