Development Of Aluminum-ion Batteries Research Articles

Engineering ternary hydrated eutectic electrolytes to realize rechargeable cathode-free aluminum-ion batteries

Aluminum-ion batteries (AIBs) have been highlighted as a promising candidate for large-scale energy storage due to the abundant reserve, low cost, high specific capacity, and good safety of aluminum. However, the development of AIBs is hindered by the usage of expensive, corrosive, and humidity-sensitive AlCl3-based ionic liquid electrolytes. Herein, we develop a low-cost, non-corrosive, and air-stable ternary hydrate eutectic electrolyte (HEE) composed of aluminum nitrate hydrate, manganese nitrate hydrate, and N,N-dimethylacetamide for cathode-free AIBs. The solvation structure of metal cations and water state in the electrolyte are regulated through the coordination of both water and N,N-dimethylacetamide molecules. The unique structural features of the HEE enables reversible deposition/stripping of AlxMnO2 on the cathodic current collector that are confirmed by various in-situ and ex-situ characterizations, ultimately realizing cathode-free AIBs. The architected cathode-free AIB delivers a discharge specific capacity of 361 mAh g−1 and shows good cycling stability and high air stability. This study provides a valuable insight into the design of rechargeable multi-valent metal ion batteries for advanced large-scale energy storage systems.

Dual–ion symmetric hybrid supercapacitor built by vanadium oxide with expanded interlayers: The intercalation of cation–anion pair and reversible redox of anion excited by Al3+

The development of aluminum ion batteries (AIBs) is retarded by the low capacity of intercalation cathode and ineffective aluminum dissolution/deposition at Al anode. To solve the issues, benzoquinone(BQ)–preinserted hydrated vanadium oxide formulated as (BQ)0.04V2O5·0.87H2O (BQ-VO) with a large interlayer spacing of 13.3 Å was synthesized, which was used as both cathode and anode with Al(ClO4)3 acetonitrile (AN) electrolyte to fabricate a symmetric aluminum–ion supercapacitor. BQ-VO delivers a large capacity of ~152 mAh g−1 at 0.2 A g−1 in the range of 0–1.5 V, which is associated with the intercalation of ion (such as ClO4−, Al3+ or Al3+ − ClO4− pair) into BQ-VO and the reversible redox reaction of ClO4− ↔ Cl−, giving rise to a novel symmetric dual–ion hybrid supercapacitor. The reversible conversion of ClO4− ↔ Cl− is not observed in NaClO4 AN electrolyte, which is only excited by Al3+, leading to a continuous increasing capacity in the early stage of the cycling test. On the contrary, in the NaClO4 AN electrolyte, BQ-VO illustrates a surface-controlled capacitive performance with excellent cycling stability. Molecular dynamic (MD) simulations reveal that Al3+ and Na+ possess different solvation/anion sheaths, leading to different electrochemical performances of BQ-VO in the Al(ClO4)3 and NaClO4 electrolytes. The present work provides a routine to utilize the redox reaction of halide for energy storage.

Aluminum intercalation behaviours of {[Fe(Tp)(CN)3]2[M(H2O)2]} cyanido-bridged chain compounds in an ionic liquid electrolyte.

As the development of aluminum-ion batteries is still in its infancy, researchers are still dedicated to exploring suitable host materials and investigating their aluminum intercalation behaviours. Here, a series of cyanido-bridged chain compounds with the formula {[FeIII(Tp)(CN)3]2[MII(H2O)2]}n (M = Ni, Co, Mn, Zn, Cu) are studied as cathode electrodes for aluminum-ion batteries with [EMIm]Cl-AlCl3 (1-ethyl-3-methylimidazolium chloride-AlCl3) ionic liquid as the electrolyte. The electrochemical properties suggested Fe3+/Fe2+ to be the redox-active couple during the aluminum intercalation and deintercalation processes of these compounds, and the observed maximum specific capacity obtained by the Fe-Co compound is 200 mA h g-1 despite the rapid specific capacity fading. To gain a deeper understanding of the capacity decay suffered by these compounds, further investigation was conducted to explore the evolution of compounds during the electrochemical measurements. It has been attributed to the following reasons: 1. thermodynamic instability results in the transformation/damage of two of the chain structures (for the Fe-Ni and Fe-Co compounds) during heat treatment on electrodes, a crucial step in electrode preparation; 2. the acidic nature of the electrolyte triggers the destruction of the chain structure, with the appearance of partial reduction of Fe3+ to Fe2+, and a new interaction of the cyano group with aluminum; 3. the high charge density of inserted Al ions makes the chain structure suffer from structural damage during both the charging and discharging processes. The progressive accumulation of trapped intercalated ions hampers their involvement in the reaction, consequently decreasing electrochemical reversibility.

Synergistic co-embedding of metal ions and hydrogen protons for high stability double salt aqueous aluminum battery

As a favorable competitor of the next generation for large-scale energy storage components, aluminum batteries (ABs) have received attention from all walks of life. However, the air sensitivity and corrosiveness of non-aqueous electrolytes seriously hinder the further development of aluminum ion batteries (AIBs). ABs meet the needs of green development and become a key research object. An excellent performance is reflected in the energy storage system of Al/4 M Al(OTF)3+1M Ca(OTF)2(4Al+Ca)/AlxMnO2·nH2O. It has an excellent discharge platform of 1.5 V, and can still maintain a high specific capacity of 233 mAh/g after 100 cycles. The co-intercalation of metal ions and protons has been demonstrated by EELS and SSNMR. What is most interesting is that during discharging, Ca2+ has the dual function of balancing charge and supporting material. MnO undergoes in-situ electrochemical conversion during charging and combines with Al3+ to form AlxMnO2·nH2O. In addition, the elaboration of the ion diffusion and solvation strategies inside the double-salt electrolyte is also an important exploration for the further development of aqueous aluminum batteries (AABs).

Organopolysulfides as high-performance cathode materials for rechargeable aluminum-ion batteries

The development of aluminum-ion batteries (AIBs) is significantly confined by the limited high-performance cathode materials. Herein, organopolysulfides are investigated as active cathode materials to fabricate AIBs. A liquid-phase phenyl tetrasulfide (PTS) can deliver a capacity above 600 mAh g−1 after activation, with the maintenance of 253 mAh g−1 after 100 cycles. Owing to the different S locations, PTS shows several voltage plateaus and an average voltage of ∼0.7 V vs. Al3+/Al with no decay upon cycling. More importantly, the liquid PTS can serve as a high-Coulombic-efficiency cathode (∼99.88% ± 0.57% after stabilization), enlighting the design of high-efficiency and low-resistance conversion-type cathode materials for AIBs. By experimental characterizations accompanied by theoretical calculations, it is found that PTS undergoes stepwise reaction procedures during discharge with final products of Al2S3 and AlCl2-coordinated phenyl sulfide, and partially reforms with elemental S and other organopolysulfides during charge. This study demonstrates new opportunities for the design of high-efficiency conversion-type cathode materials for advanced AIBs.

Novel Bimetallic Activated Center Alloying Mechanism Positive Electrodes for Aluminum Storage.

Aluminum is the most abundant metal element in the Earth's crust, thus developing the rechargeable aluminum-ion batteries (AIBs) provides an ideal opportunity to realize cells with pleasing energy-to-price ratios. However, the further development of AIBs is plagued by the scarcity of suitable positive electrode materials. Here, for the first time, a tin-based alloy positive electrode material for AIBs, Co3 Sn2 wrapped with graphene oxide (Co3 Sn2 @GO composite) is well-designed and investigated to understand the aluminum storage behavior. A series of experimental measurements and theoretical calculations results reveal that a novel "bimetallic activated center alloying reaction" aluminum storage mechanism is occurred on the prepared Co3 Sn2 positive electrode. The reversible alloying/de-alloying process in AlCl3 /[EMIm]Cl ionic liquid, where both Co and Sn in Co3 Sn2 alloys react electrochemically with Al3+ to form Alx Sn and Aly Co is first put forward. This study delineates new insights on the aluminum storage mechanism, which may guide to ultimately exploit the energy benefits of "bimetallic activated center alloying redox".

Stable WS2/WO3 Composites as High-Performance Cathode for Rechargeable Aluminum-Ion Batteries

Aluminum-ion batteries have become a promising energy storage device due to their low cost, large volume specific capacity, and environmental friendliness. Due to the poor reversibility and conductivity of traditional electrode materials, the development of aluminum-ion batteries has been greatly hindered. In this paper, a new stable WS2/WO3 cathode for aluminum-ion batteries was prepared by the coprecipitation method. The introduction of the WS2/WO3 heterojunction greatly enhances the electron transfer rate between the material interfaces, and the large specific surface area of the material also provides more active sites for the electrochemical reaction. The WS2/WO3 cathode retained a high specific capacity of 200 mAh/g with a capacity retention of 80% at 1000 mA/g after 100 cycles.

A Low-Cost and Air-Stable Rechargeable Aluminum-Ion Battery.

Rechargeable aluminum-ion batteries (AIBs) are promising for large-scale energy storage due to the abundant reserves, low cost, and high capacity of the Al anode. However, the development of AIBs is currently hindered by the usage of AlCl3 /1-ethyl-3-methylimidazolium chloride electrolyte, which is expensive, highly corrosive, and extremely air-sensitive. Herein, a new hydrated eutectic electrolyte (HEE) composed of hydrated aluminum perchlorate and succinonitrile for low-cost, noncorrosive, and air-stable AIBs is reported. Crystal water in the hydrated aluminum perchlorate plays a vital role in forming the HEE, in which one H2 O and five succinonitrile molecules coordinate with one Al3+ ion. The optimized ratio of Al(ClO4 )3 ·9H2 O to succinonitrile is 1:12. When combining with the self-doped polyaniline cathode, the associated AIB delivers a high discharge capacity of 185 mAh g-1 over 300 cycles; and the charge/discharge mechanism in the HEE is studied experimentally and theoretically. The HEE is nonflammable, air-stable, and noncorrosive, thus enabling good air tolerance and facile fabrication of AIBs.

β-Hydrogen of Polythiophene Induced Aluminum Ion Storage for High-Performance Al-Polythiophene Batteries.

The urgent need for large-scale, low-cost energy storage has driven a new wave of research focusing on innovative batteries. Due to the high capacity and the low-cost of elemental Al, aluminum-ion batteries (AIBs) are expected as promising candidates for future energy storage. However, further development of AIBs is restricted by the performance of existing carbon-based cathodes and metal chalcogenide cathode materials. In this work, we deposited polythiophene (Pth) on a graphene oxide (Pth@GO) composite and used it as an AIB cathode material. This Pth@GO composite possesses high exposure of Pth active sites, high conductivity, and high structure stability while providing a very high discharge capacity (up to 130 mAh g-1) and outstanding cyclic stability (maintaining above 100 mAh g-1 after 4000 cycles). First principles calculations and experimental results show that the charge is stored on Pth@GO through an electrostatic attraction between AlCl4- and β-hydrogen (Cβ-H) sites in polythiophene.

Porous CuO microsphere architectures as high-performance cathode materials for aluminum-ion batteries

Cathode materials with a porous structure are important in the development of aluminum-ion batteries (AIBs).

Aluminum-based materials for advanced battery systems

There has been increasing interest in developing micro/nanostructured aluminum-based materials for sustainable, dependable and high-efficiency electrochemical energy storage. This review chiefly discusses the aluminum-based electrode materials mainly including Al2O3, AlF3, AlPO4, Al(OH)3, as well as the composites (carbons, silicons, metals and transition metal oxides) for lithium-ion batteries, the development of aluminum-ion batteries, and nickel-metal hydride alkaline secondary batteries, which summarizes the methodologies, related charge-storage mechanisms, the relationship between nanostructures and electrochemical properties found in recent years, latest research achievements and their potential applications. In addition, we raise the relevant challenges in recently developed electrode materials and put forward new ideas for further development of micro/nanostructured aluminum-based materials in advanced battery systems.