Chloride Ion Batteries Research Articles

Super Chloride Ionic Conductivity in CsSnCl3‐Based Perovskite Compound and Its Application for Solid‐State Chloride Batteries

A CsSnCl3‐based solid electrolyte in which 5% of Sn sites are occupied by Y ions, CsSn0.95Y0.05Cl3.05 (CSYC), is developed using a one‐step mechanical ball‐milling method. CSYC exhibits a stable cubic perovskite crystal structure and a high chloride ion conductivity of 4.9 mS cm−1. The relative density of a CSYC pellet following cold pressing without heat treatment is 97.5%. The high relative density and ionic conductivity are considered to originate from the high mechanical plasticity of the pellets, as evidenced by a low Young's modulus of 8.2 GPa. An all‐solid‐state chloride ion battery cell using CSYC as the electrolyte, BiCl3 as the active cathode material, and Sn as the anode is confirmed to operate at room temperature. The cell shows a large initial discharge capacity of 178 mAh g−1, ≈70% utilization, and good capacity retention with a reversible capacity of 100 mAh g−1 after 40 cycles. The mechanical plasticity of CSYC is considered to be a major contributor to its high ionic conductivity and good battery cycling performance.

Rechargeable Seawater-Based Chloride-Ion Batteries Enabled by Covalent Surface Chemistry in MXenes.

Rechargeable aqueous chloride-ion batteries (ACIBs) using Cl- ions as charge carriers represent a promising energy-storage technology, especially when natural seawater is introduced as the electrolyte, which can bring remarkable advantages in terms of cost-effectiveness, safety, and environmental sustainability. However, the implementation of this technology is hindered by the scarcity of electrodes capable of reversible chloride-anion storage. Here, we show that a Ti3C2Clx MXene with Cl surface terminations enables reversible Cl- ion storage in aqueous electrolytes. Further, we developed seawater-based ACIBs that show a high specific capacity and an exceptionally long lifespan (40000 cycles, more than 1 year) in natural seawater electrolyte. The pouch-type cells achieve a high energy density (50 Wh Lcell-1) and maintain stable performance across a broad temperature range (-20 to 50 °C). Our investigations reveal that the covalent interaction between Cl- ions and Cl-terminated MXene facilitates Cl- ion intercalation into the MXene interlayer, promoting rapid ion migration with a low energy barrier (0.10 eV). Moreover, this MXene variant also enables the reversible storage of Br- ions in an aqueous electrolyte with a long cycle life. This study may advance the design of anion storage electrodes and enable the development of sustainable aqueous batteries.

Interlayer-spacing regulation of NiFe LDH nanosheets cathode with high rate performance for chloride ion battery

Chloride ion batteries (CIBs) possess the multiple advantages of high theoretical volumetric energy density, abundant precursor resources and high safety due to the dendrit-free characteristic, which provide more choices and opportunities for electrochemical energy storage. In this work, NiFe LDH nanosheets with different interlayer spacing are prepared using a simple co-precipitation method with the interlayer spacing of LDH nanosheets extended from 7.695 Å to 24.114 Å. Expanding interlayer space of LDHs nanoplates helps to the promote ion diffusion and enhance their action kinetics. Additionally, the increased oleophobicity between NiFe LDH nanosheets cathode with increased interlayer spacing and solvent PC is beneficial for the structural stability of the materials during cycling. Compared with typical chloride ion-intercalated NiFe LDH nanosheets, the NiFe-C17H25O3 LDH with the maximum interlayer spacing demonstrates a performance improvement of about 213 % (with a discharge specific capacity of 64.2 mAh/g after 200 cycles) at high current density and good rate performance. This work provides a simple and effective interlayer spacing control strategy for the design of CIBs cathodes under high current density.

Crown Ether Electrolyte Additive Enables High-Rate and Stable Polyviologen Cathode Material for Chloride Ion Batteries.

A variety of inorganic and inorganic cathode materials for chloride ion storage are reported. However, their application in chloride ion batteries (CIB) is hindered by poor rate capability and cycling stability. Herein, an organic poly(butyl viologen dichloride) (PBVCl2) cathode material with significantly enhanced rate and cycling performance in the CIB is achieved using a crown ether (18-Crown-6) additive in the tributylmethylammonium chloride-based electrolyte. The as-prepared PBVCl2 cathodes exhibit impressive capacity increases from 149.4 to 179.1 mAh g-1 at 0.1 C and from 57.8 to 111.9 mAh g-1 at 10 C, demonstrating the best rate performance with the highest energy density among those of various reported cathodes for CIBs. This impressive performance improvement is a result of the great boosts in charge transfer, ion transport, and interface stability of the battery by the use of 18-Crown-6, which also contributes to a more than twofold increase in capacity retention after 120 cycles. The electrode reaction mechanism of the CIB based on highly reversible chloride ion transfer is revealed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy.

Design of Solid Polycationic Electrolyte to Enable Durable Chloride-Ion Batteries.

The high energy density and cost-effectiveness of chloride-ion batteries (CIBs) make them promising alternatives to lithium-ion batteries. However, the development of CIBs is greatly restricted by the lack of compatible electrolytes to support cost-effective anodes. Herein, we present a rationally designed solid polycationic electrolyte (SPE) to enable room-temperature chloride-ion batteries utilizing aluminum (Al) metal as an anode. This SPE endows the CIB configuration with improved air stability and safety (i.e. free of flammability and liquid leakage). A high ionic conductivity (1.3×10-2 S cm-1 at 25 °C) has been achieved by the well-tailored coordination structure of the SPE. Meanwhile, the solid polycationic electrolyte ensures stable electrodes|electrolyte interfaces, which effectively inhibit the growth of dendrites on the Al anodes and degradation of the FeOCl cathodes. The Al|SPE|FeOCl chloride-ion batteries showcased a high discharge capacity around 250 mAh g-1 (based on the cathodes) and extended lifespan. Our electrolyte design opens a new avenue for developing low-cost chloride-ion batteries.

Design of Solid Polycationic Electrolyte to Enable Durable Chloride‐Ion Batteries

AbstractThe high energy density and cost‐effectiveness of chloride‐ion batteries (CIBs) make them promising alternatives to lithium‐ion batteries. However, the development of CIBs is greatly restricted by the lack of compatible electrolytes to support cost‐effective anodes. Herein, we present a rationally designed solid polycationic electrolyte (SPE) to enable room‐temperature chloride‐ion batteries utilizing aluminum (Al) metal as an anode. This SPE endows the CIB configuration with improved air stability and safety (i.e. free of flammability and liquid leakage). A high ionic conductivity (1.3×10−2 S cm−1 at 25 °C) has been achieved by the well‐tailored coordination structure of the SPE. Meanwhile, the solid polycationic electrolyte ensures stable electrodes|electrolyte interfaces, which effectively inhibit the growth of dendrites on the Al anodes and degradation of the FeOCl cathodes. The Al|SPE|FeOCl chloride‐ion batteries showcased a high discharge capacity around 250 mAh g−1 (based on the cathodes) and extended lifespan. Our electrolyte design opens a new avenue for developing low‐cost chloride‐ion batteries.

FeOCl/polyaniline nanosheets as high-performance cathode for chloride ion battery

Chloride-ion batteries (CIBs) are potentially low-cost and safe alternatives to lithium-ion batteries. As a promising cathode material for CIBs, iron oxychloride shows high theoretical capacity and rich resources. However, the huge volumetric expansion and shrinkage issue for the phase transition result in pulverization of FeOCl particles and structural collapse of electrodes. Herein, FeOCl/polyaniline nanosheets with expanded laminated structure, polyaniline-coated, and high chlorine content have been developed as a high-performance cathode material for CIBs. It was found that the slow in situ intercalation polymerization of aniline into the layer of FeOCl nanosheets results in an irreversible loss of chlorine content, which is unfavorable for high discharge capacity. After being completely intercalated, adding an oxidizing agent is conducive to the polymerization of aniline and keeping the chlorine content stable. As a result, the optimized FeOCl/polyaniline cathode exhibits the highest discharge capacity of 187 mAh·g−1, and a capacity retention of 85.0 % after 50 cycles. Polyaniline was maintained in the doped state and acted as a volume buffering matrix during the cycles.

Constructing in-situ polymerized electrolyte for room-temperature solid-state chloride ion battery with enhanced electrochemical performance

Considering large volume variation and dissolution issues of some promising electrode materials for chloride ion batteries (CIB), the construction of solid polymer electrolytes (SPE) for efficient chloride ion transport is intriguing. However, this is hindered by low ionic conductivity of chloride SPEs and poor cycling performance of CIBs. Herein, an in-situ polymerized and cross-linked poly(ethylene glycol) diacrylate-based chloride SPE with a low plasticizer content of succinonitrile is designed, yielding a room-temperature ionic conductivity of 7.6 × 10−5 S cm−1, which is higher than that of previously reported SPEs for CIBs. Moreover, the use of the as-prepared SPE achieves an integrated organic cathode with significantly enhanced rate performance and capacity retention of 96.1 % after 100 cycles at room temperature, which is much higher than 49.9 % (80 cycles) of the cathode in the CIB with a sandwiched structure. These improved properties are also superior to that of other reported cathodes coupled with different chloride SPEs. The chloride ion transfer mechanism of the cathode is revealed by X-ray photoelectron spectroscopy and energy dispersive spectroscopy.

Exploration of Electrode‐Electrolyte‐in‐One System Based on Fluorine/Chloride Ion Battery

AbstractWith an increasingly profound understanding of battery materials, strategies designed for interface protection have become more sophisticated. However, it is inherent that different materials used in electrodes and electrolytes tend to react with each other. To address this issue, this study proposes an “Electrode‐Electrolyte‐In‐One” (EEIO) concept, where a single energy storage material can serve as both electrode and solid‐state electrolyte (SSE) during its different ion storage stages. The EEIO materials of chloride ion batteries and fluorine ion batteries are preliminarily studied, establishing reasonable screening procedures and predicting their operational mechanisms. The analysis of Cl− and F− affinity indicates that the EEIO system in the anion storage batteries comprises the anode and SSE. Through comprehensive evaluation of ion binding capacity, phase transformation mechanism, electrical conductivity, and ion diffusion kinetic properties, several potential EEIO materials are identified. In the EEIO system, the material interface and the conductive‐insulation interface are separated, which solves the material compatibility problem between the anode and SSE. Furthermore, the EEIO system has an inherent correlation between the anode electrochemical reaction and the SSE decomposition reaction, ensuring that the electrochemical voltage of EEIO batteries never exceeds the decomposition voltage of SSE. Therefore, SSE in the EEIO battery has absolute electrochemical stability.

Effect of Cobalt on Lifetime of Sb4O5Cl2-Graphene Anode in Chloride-Ion Batteries.

Anode materials based on metal oxychlorides hold promise in addressing electrode dissolution challenges in aqueous-based chloride ion batteries (CIBs). However, their structural instability following chloride ion deintercalation can lead to rapid degradation and capacity fading. This paper investigates a cobalt-doped Sb4O5Cl2-graphene (Co-Sb4O5Cl2@GO) composite anode for aqueous-based CIBs. It exhibits significantly enhanced discharge capacity of 82.3 mAh g-1 after 200 cycles at 0.3 A g-1; while, the undoped comparison is only 23.5 mAh g-1 in the same condition. It also demonstrated with a long-term capacity retention of 72.8 % after 1000 cycles (65.5 mAh g-1) and a favorable rate performance of 25 mAh g-1 at a high current density of 2 A g-1. Undertaken comprehensive studies via in-situ experiments and DFT calculations, the cobalt (Co) dopant is demonstrated as the crucial role to enhance the lifetime of Sb4O5Cl2-based anodes. It is found that, the Co dopant improves electronic conductivity and the diffusion of chloride ions beside increases the structural stability of Sb4O5Cl2 crystal. Thus, this element doping strategy holds promise for advancing the field of Sb4O5Cl2-based anodes for aqueous-based CIBs, and insights gain from this study also offer valuable knowledge to develop high-performance electrode materials for electrochemical deionization.

Graphene oxide coated functional separators as efficient metal chloride blocking layers for chloride ion batteries

A graphene oxide interlayer between the cathode and the separator could address the shuttle issue of metal chloride cathodes. The electrochemical performance of metal chloride cathodes was significantly enhanced.

High-throughput screening of stable layered anode materials A2TMO3Cl for chloride-ion batteries

A vacuum cleaner-like “TM–O–A–Cl” configuration simultaneously retains Cl-storage/binding capacity in A2TMO3Cl.

Battery Electrode-Based Lithium Recovery from Geothermal Brines

Driven by the electrification of transport sector the demand of lithium for battery application is increasing exponentially. The major sources for lithium are continental brines and hard minerals where the production comes along with consumptive water requirements and energy intensive processing and extraction. Therefore, it is of tremendous importance to consider alternative, non-conventional, sources and to develop more efficient and environmentally benign Li extraction methods. Geothermal brines can have significant Li concentrations (150–240 mgLi+ L−1)[1] and could represent an attractive sustainable lithium source. Implementing electrochemical methods for lithium extraction offers further advantages of high Li-selectivity, minimal waste production and low water consumption.[2] Here, we present a dual-ion battery type setup for the selective electrochemical Li-adsorption and desorption from geothermal brines. The chloride concentration in brines is a thousand times higher than that of Li+, hence, both species can be captured at opposite electrode sides. In the dual-ion setup presented in this work, Li+ are stored in a Li-selective LiFePO4(LFP) battery electrode and Cl− are stored using bismuth oxychloride (BiOCl) as counter electrode that has shown excellent Cl− storage capabilities and chemical stability in chloride-ion batteries and desalination batteries.[3] In the second step, both ions are released in a recovery solution to yield a Li-rich solution that could be further processed into battery-grade lithium hydroxide or carbonate. The stability of LFP in aqueous solutions and high Li -selectivity makes it a favored candidate for the electrochemical recovery of Li from natural solutions, where a diverse mixture of cations and anion is present.[4] Therefore, we examined the stability of the electrodes in brine solutions by XRD, indicating good reversibility and no intercalation of competitor ions. In addition, the Li-selectivity in extraction/recovery experiments was analyzed by ICP-OES and influences of different process parameters (e.g. current density, pH, temperature) were investigated. The results demonstrate that the LFP/BiOCl dual-ion battery setup is a feasible and promising low cost method for environmentally friendly Li extraction from geothermal brines.

Bismuth and Chlorine Dual-Doped Perovskite Chloride as a Phase-Structure-Stable and Moisture-Resistant Solid Electrolyte for Chloride Ion Batteries.

Perovskite chloride, an anion conductor, is a promising candidate to be a solid electrolyte for high-energy and sustainable chloride ion batteries (CIB). However, it suffers from poor structural stability at low temperature and in ambient conditions, which leads to its transformation from an ionic conductor to an insulator. Herein, a bismuth and chlorine dual doping strategy is developed to stabilize the cubic structure of CsSnCl3 in harsh environments. The as-prepared dual-doped CsSn0.9 Bi0.1 Cl3.1 material with an optimized composition maintains its cubic structure at the extremely low temperature of 213K for 10 days and at 40% relative humidity for 50 days, while the undoped cubic material deteriorates and transforms to a monoclinic phase under these conditions in less than 1 day. Consequently, the dual doping achieves efficient chloride ion conduction that is superior to single bismuth doping due to the introduction of interstitial chlorine facilitating chloride ion transport. Importantly, the practicality of the as-prepared solid electrolyte is demonstrated in different symmetric solid cells and by various CIBs using the organic electrode couple, a multivalent metal chloride cathode, or a new high-voltage metal oxychloride cathode.

Heteroatoms introduction via Temperature-Differential doping strategy achieves Long-Cycle-Life NiCoMo-P LDH cathode for rechargeable Chloride-Ion battery

As one of the most promising insertion-type cathodes for the novel chloride ion batteries (CIBs), layered double hydroxides (LDHs) materials have been extensively investigated in the recent years as the typical inorganic anion conductors. Nevertheless, poor intrinsic conductivity and sluggish reaction kinetics of LDHs challenge directly the further development in terms of chloride storage capacity and cycling life. Herein, phosphorus doped NiCoMo LDH in chloride form (NiCoMo-P LDH) is demonstrated as a high performance cathode for CIB. The unique temperature-differential doping methode allows P heteroatoms to incorporate into the metal–oxygen octahedral matrix of LDHs host layers, which have no effect on the entire crystal structure of 2D LDHs and the stable presence of interlayer Cl ions. By combining the advanced spectroscopy techniques and DFT theoretical calculations, abundant vacancies are proved to be introduced into NiCoMo-P LDH and both the conductivity and chloride-ion diffusion rate are significantly improved, providing more active adsorption sites for electrochemical reactions, thus strengthening the Cl ions storage performance with a stable discharge capacity of 150.2 after 800 charging/discharging processes at a current density of 300 mA g−1. This study presents a facile strategy for the rational doping of hetero-anions in LDHs materials for CIBs at relative low-temperature, which can also be adopted in other types of halide-ion-based rechargeable batteries.

Chlorinated phosphorene for energy application

The influence of decoration with impurities and the composition dependent band gap in 2D materials has been the subject of debate for a long time. Here, by using Density Functional Theory (DFT) calculations, we systematically disclose physical properties of chlorinated phosphorene having the stoichiometry of PmCln. By analyzing the adsorption energy, charge density, migration energy barrier, structural, vibrational, and electronic properties of chlorinated phosphorene, we found that (I) the ClP bonds are strong with binding energy Eb=-1.61eV, decreases with increasing n. (II) Cl atoms on phosphorene have anionic feature, (III) the migration path of Cl on phosphorene is anisotropic with an energy barrier of 0.38eV, (IV) the phonon band dispersion reveal that chlorinated phosphorenes are stable when r≤0.25 where r=m/n, (V) chlorinated phosphorenes is found to be a photonic crystal in the frequency range of 280cm−1 to 325cm−1, (VI) electronic band structure of chlorinated phosphorenes exhibits quasi-flat bands emerging around the Fermi level with widths in the range of 22meV to 580meV, and (VII) Cl adsorption causes a semiconducting to metallic/semi-metallic transition which makes it suitable for application as an electroactive material. To elucidate this application, we investigated the change in binding energy (Eb), specific capacity, and open-circuit voltage as a function of the density of adsorbed Cl. The theoretical storage capacity of the chlorinated phosphorene is found to be 168.19mAhg−1 with a large average voltage (∼2.08V) which is ideal number as a cathode in chloride-ion batteries.

NiTi-Layered Double Hydroxide@Carbon Nanotube as a Cathode Material for Chloride-Ion Batteries.

Chloride-ion batteries (CIBs) are one of the promising candidates for energy storage due to their low cost, high theoretical energy density and high safety. However, the limited types of cathode materials in CIBs have hindered their development. In this work, a NiTi-LDH@CNT composite is prepared using a reverse microemulsion method and applied in CIBs for the first time. The specific surface area and the pore volume of the obtained NiTi-LDH@CNT composites can reach 266 m2 g-1 and 0.42 cm3 g-1, respectively. Electrochemical tests indicate that the composite electrode delivers a reversible specific capacity of 69 mAh g-1 after 150 cycles at a current density of 100 mA g-1 in 0.5 M PP14Cl/PC electrolyte. Ni2+/Ni3+ and Ti3+/Ti4+ valence changes during electrochemical cycling are demonstrated by X-ray photoelectron spectroscopy (XPS), while reversible migration of Cl- is revealed by ex-situ EDS and ex-situ XRD. The stable layered structure and abundant valence changes of the NiTi-LDH@CNT composite make it an exceptional candidate as a cathode material for CIBs.

Aqueous Chloride-Ion Battery within a Neutral Electrolyte Based on a CoFe-Cl Layered Double Hydroxide Anode.

Aqueous chloride-ion batteries (ACIBs) with environmental friendliness and high safety hold great potential to fulfill the green energy demand for ocean desalination. Herein, for the first time, a composite consisting of Cl--intercalated CoFe layered double hydroxides (CoFe-Cl-LDH) cross-linked with CNTs (CoFe-Cl-LDH/CNT) is synthesized and demonstrated to be a novel high-performance anode for ACIBs in a neutral NaCl aqueous solution. While exhibiting a high initial capacity of ∼190 mAh g-1 at 200 mA g-1, CoFe-Cl-LDH/CNT is capable of delivering a reversible capacity of ∼125 mAh g-1 after 200 cycles. At a high current density of 400 mA g-1, it still holds a capacity of ∼120 mAh g-1. The excellent Cl- storage performance can be contributed to the unique topochemical transformation feature that reverses intercalation/deintercalation of Cl- along with valence changes of Co2+/Co3+ and Fe2+/Fe3+ during charge/discharge and the improved electronic conductivity by hybridizing with CNTs. It is interesting that the invertible insertion/extraction of interlayer H2O was discovered, which could be beneficial to the capacity after cycles to a certain extent. The Cl--intercalated LDH material declared in this work shows its feasibility on Cl- capture/release in aqueous anion-type batteries and provides a new opportunity for future development of ACIBs or aqueous desalination technology.

Ethylene carbonate plasticized polymer electrolyte for chloride ion batteries with enhanced reversible capacity

Chloride ion batteries (CIB) are attracting more and more attention in recent years because of abundant chloride sources, high energy density, and high safety. The electrode dissolution into the liquid electrolyte remains a great challenge in CIBs. Exploring solid polymer electrolyte provides a feasible solution to address this issue. Herein, a novel gel polymer electrolyte composed of poly(ethylene oxide) (PEO) as a host polymer, tributylmethylammonium chloride (TBMACl) as a salt, and ethylene carbonate (EC) as a plasticizer was prepared by a solution casing method. The addition of plasticizer can not only decrease the PEO crystallinity but also increase salt dissociation. As a result, the ionic conductivity of the plasticized PEO-TBMACl-EC polymer electrolyte reached 5.27 × 10−5 S cm−1 at room temperature, which is much higher than 3.45 × 10−7 S cm−1 of the unplasticized PEO-TBMACl polymer electrolyte. When assembled into CIBs with the FeOCl/Li electrode couple, higher reversible capacities were achieved with the plasticized PEO-TBMACl-EC polymer electrolyte compared to unplasticized PEO-TBMACl polymer electrolyte.

A High-Nickel Layered Double Hydroxides Cathode Boosting the Rate Capability for Chloride Ion Batteries with Ultralong Cycling Life.

Chloride-ion batteries (CIBs) have drawn growing attention in large-scale energy storage applications owing to their comprehensive merits of high theoretical energy density, dendrite-free characteristic, and abundance of chloride-containing materials. Nonetheless, cathodes for CIBs are plagued by distinct volume effect and sluggish Cl- diffusion kinetics, leading to inferior rate capability and short cycling life. Herein, an unconventional Ni5 Ti-Cl LDH is reported with a high nickel ratio as a cathode material for CIB. The reversible capacity of Ni5 Ti-Cl LDH retains 127.9 mAh g-1 over 1000 cycles at a large current density of 1000mA g-1 , which exceeds that of ever reported CIBs, with extraordinary low volume change of 1.006% during a whole charge/discharge process. Such superior Cl-storage performance is attributed to synergetic contributions consisting of high redox activity from Ni2+ /Ni3+ and pinning Ti that restrains local structural distortion of LDH host layers and enhances adsorption intensity of chloride atoms during the reversible Cl- intercalation/de-intercalation in LDH gallery, which are revealed by a comprehensive study including X-ray photoelectron spectroscopy, kinetic investigations, and DFT calculations. This work provides an effective strategy to design low-cost LDHs materials for high-performance CIBs, which are also applicable to other types of halide-ion batteries (e.g., fluoride-ion and bromide-ion batteries).