Metal-based Batteries Research Articles

Lithium metal based battery systems with ultra-high energy density beyond 500 W h kg-1.

As industries and consumption patterns evolve, new electrical appliances are increasingly playing critical roles in national production, defense, and cognitive exploration. However, the slow development of energy storage devices with ultra-high energy density (beyond 500 W h kg-1) has impeded the promotion and widespread application of the next generation of intelligent, multi-scenario electrical equipment. Among the numerous ultra-high specific energy battery systems, lithium metal batteries (LMBs) hold significant potential for applications in advanced and sophisticated fields. This potential is primarily due to lithium metal's high specific capacity (3860 mA h g-1). However, LMBs face numerous challenges, including the growth of lithium dendrites, poor cycle stability, and safety concerns. In recent years, research on the mechanisms of Li metal-based battery systems, innovation in electrode materials, and optimization of device configurations have made significant progress. In this highlight, we provide a comprehensive overview of the storage mechanisms and the latest advancements in high-energy-density LMBs, represented by systems such as Li-Li1-xMO2, Li-S/Se, Li-gas (CO2/air/O2), Li-CFx, and all-solid-state LMBs. By integrating the current research findings, we highlight the opportunities and future research directions for high-energy-density LMBs, offering new guiding perspectives for their development under practical conditions.

Heteroatom Immobilization Engineering toward High-Performance Metal Anodes.

Heteroatom immobilization engineering (HAIE) is becoming a forefront approach in materials science and engineering, focusing on the precise control and manipulation of atomic-level interactions within heterogeneous systems. HAIE has emerged as an efficient strategy to fabricate single-atom sites for enhancing the performance of metal-based batteries. Despite the significant progress achieved through HAIE in metal anodes for metal-based batteries, several critical challenges such as metal dendrites, side reactions, and sluggish reaction kinetics are still present. In this review, we delve into the fundamental principles underlying heteroatom immobilization engineering in metal anodes, aiming to elucidate its role in enhancing the electrochemical performance in batteries. We systematically investigate how HAIE facilitates uniform nucleation of metal in anodes, how HAIE inhibits side reactions at the metal anode-electrolyte interface, and the role of HAIE in promoting the desolvation of metal ions and accelerating reaction kinetics within metal-based batteries. Finally, we discuss various strategies for implementing HAIE in electrode materials, such as high-temperature pyrolysis, vacancy reduction, and molten-salt etching and anchoring. These strategies include selecting appropriate heteroatoms, optimizing immobilization methods, and constructing material architectures. They can be utilized to further refine the performance to enhance the capabilities of HAIE and facilitate its widespread application in next-generation metal-based battery technologies.

Reversible storage of tetraethyl ammonium cation in CFx-based cathode

Carbon fluorides (CFx) are considered as the potential cation storage materials in alkali metal-based battery systems because of the high theoretical specific capacity (865 mAh g-1 when x = 1). However, the reversibility of cathode reaction is seriously disturbed by the strong metal-fluorine interactions among the electrode products (e.g., LiF). By contrast, the relatively weak N-F bond makes the CFx-based battery system using quaternary ammonium cation (QAA+) a promising alternate, but the electrode mechanism between CFx and QAA+is little understood yet. In this work, tetraethylammonium cation (TEA+) is employed as the charge carrier using the electrolyte solution of sulfolane (SL) for CFx cathode. The CF0.56 electrode exports 710 mAh g-1 during the initial TEA+-CF reaction, and the electrode product (TEAF) can be decomposed under elevated potential that yields amorphous carbon fluoride and a reversible capacity of ∼300 mAh g-1 can be reached in the subsequent galvanostatic charge-discharge cycles. The TEAF product is non-crystallizable that exists in a sticky form on the surface of electrode, which contributes to an improved electrode structural stability while also leads to an unsatisfactory performance of the amorphous carbon fluoride with large number of superficial active sites. The electrode mechanism and the mechanical property of electrode interface are discussed in depth by in-situ Raman and electrochemical quartz crystal microbalance (EQCM) methods.

A Bifunctional Carbon-LiNO3 Composite Interlayer for Stable Lithium Metal Powder Electrodes as High Energy Density Anode Material in Lithium Batteries

Lithium metal remains a promising candidate for high-energy-density rechargeable batteries due to its exceptional specific capacity and low reduction potential. However, practical implementation of lithium metal anodes faces challenges such as dendrite formation, limited cycle life, and safety concerns. This study introduces a novel approach to enhance the performance of lithium metal powder (LMP)-based electrodes by embedding a LiNO3-carbon composite interlayer between the LMP electrode and the copper foil current collector. The N-rich carbon interlayer acts as a reservoir for LiNO3, enabling its gradual release to maintain prolonged stability of the interfacial reactions of the Li-metal and providing additional Li nucleation sites. Our findings demonstrate that the LiNO3-carbon composite effectively suppresses dendrite formation, improves reversible capacity, and stabilizes the solid electrolyte interphase. Additionally, we validated the fast-charging capabilities of the Li/NCM622 half-cell employing the LiNO3-carbon-coated Cu foil with LMP electrodes. Our results highlight the significant synergistic effect of the LiNO3 additive and carbon interlayer in enhancing the performance of lithium metal-based batteries.

One-step and universal fabrication of MXene/metal sodiophilic frameworks via Lewis acidic etching toward dendrite-free sodium metal anodes

Although MXene-based 3D scaffolds have boosted the cyclability of Na metal, the complex and harsh synthetic process deteriorates their practical application. Herein, a series of MXene/metal sodiophilic frameworks are constructed through one-step Lewis acidic etching, and metal nanoparticles are uniformly distributed on the surface or intercalated into the large interlayer gaps of MXenes. Notably, MXenes with superior Na+/electron transport kinetics and mechanical flexibility remarkably reduce the local current density, homogenize Na+ flux and cushion huge volume change of Na metal. Moreover, sodiophilic species including MXenes and metals effectively induce Na uniform nucleation and smooth deposition among the 3D matrixes, leading to dendrite-free morphology. Consequently, MXene/metal hosts exhibit stable Na plating/stripping process for 900 cycles with high average Coulombic efficiencies of 99.9% (2 mA cm−2, 1 mAh cm−2). The MXene/metal-Na symmetric cells achieve low overpotentials of less than 15 mV and stable cycling for 2200 h (2 mA cm−2, 4 mAh cm−2). When paired with Na3V2(PO4)3 cathode, the full cells with a low N/P ratio (around 2) demonstrate high discharge capacity and excellent long-term cyclic performance over 600 cycles. The presented universal, safe and one-step approach in fabricating MXene/metal scaffolds shows bright prospects and may promote the development of alkali metal-based batteries.

Dipole Moment Influences the Reversibility and Corrosion of Lithium Metal Anodes.

Lithium metal batteries (LMBs) must have both long cycle life and calendar life to be commercially viable. However, "trial and error" methodologies remain prevalent in contemporary research endeavors to identify favorable electrolytes. Here, a guiding principle for the selection of solvents for LMBs is proposed, which aims to achieve high Coulombic efficiency while minimizing the corrosion. For the first time, this study reveals that the dipole moment and orientation of solvent molecules have significant impacts on lithium metal reversibility and corrosion. Solvents with high dipole moments are more likely to adsorb onto lithium metal surfaces, which also influence the solid electrolyte interphase. Using this principle, the use of LiNO3 is demonstrated as the sole salt in LiNi0.8Co0.1Mn0.1O2/Li cells can achieve excellent cycling stability. Overall, this work bridges the molecular structure of solvents to the reversibility and corrosion of lithium metal, and these concepts can be extended to other metal-based batteries.

General Fabrication of Robust Alloyed Metal Anodes for High-Performance Metal Batteries.

Revitalizing metal anodes for rechargeable batteries confronts challenges such as dendrite formation, limited cyclicity, and suboptimal energy density. Despite various efforts, a practical fabrication method for dendrite-free metal anodes remains unavailable. Herein, focusing on Li as exemplar, a general strategy is reported to enhance reversibility of the metal anodes by forming alloyed metals, which is achieved by induction heating of 3D substrate, lithiophilic metals, and Li within tens of seconds. It is demonstrated that preferred alloying interactions between substrates and lithiophilic metals created a lithiophilic metal-rich region adjacent to the substrate, serving as ultrastable lithiophilic host to guide dendrite-free deposition, particularly during prolonged high-capacity cycling. Simultaneously, an alloying between lithiophilic metals and Li creates a Li-rich region adjacent to electrolyte that reduces nucleation overpotential and constitutes favorable electrolyte-Li interface. The resultant composite Li anodes paired with high areal loading LiNi0.8Co0.1Mn0.1O2 cathodes achieve superior cycling stability and remarkable energy density above 1200 Wh L-1 (excluding packaging). Furthermore, this approach shows broader applicability to other metal anodes plagued by dendrite-related challenges, such as Na and Zn. Overall, this work paves the way for development of commercially viable metal-based batteries that offer a combination of safety, high energy density, and durability.

Core-shell-structured NiCo2O4 composite with GO/C to enhance its electrocatalytic performance as a cathode catalyst in zinc-air batteries

This study employed a simple and effective method to synthesize a composite material comprising core-shell NiCo2O4 and GO/C. The combination of core-shell NiCo2O4 and GO effectively improved the poor conductivity of NiCo2O4 and prevented the aggregation of NiCo2O4 microspheres. In electrochemical tests, compared to pure core-shell NiCo2O4, NiCo2O4@GO/C exhibits improved catalytic performance in both oxygen reduction (ORR) and oxygen evolution reactions (OER). Its OER catalytic performance is notably superior to that of noble metal catalysts. The NiCo2O4@GO/C-based liquid-state zinc-air battery exhibited a stable cycling efficiency of 51% over 200 h of charge-discharge cycles, significantly outperforming precious metal-based batteries. Additionally, a flexible quasi-solid-state zinc-air battery, assembled with the NiCo2O4@GO/C composite material as the cathode catalyst, exhibited an outstanding cycling efficiency of 58% in charge-discharge cycles. These results indicate that the NiCo2O4@GO/C composite material holds great potential as a bifunctional electrocatalytic catalyst for zinc-air batteries.

In situ catalytic polymerization of LiNO3-containing PDOL electrolytes for high-energy quasi-solid-state lithium metal batteries

1,3-Dioxolane (DOL) can be induced to form polymer electrolytes by in situ ring opening polymerization at Lewis acid salts. However, the presence of ion–dipole interactions between NO3− and DOL suppresses this polymerization behavior. Herein, we report that the use of Sc(OTf)3 as an initiator can well disrupt this ion–dipole interaction. The in situ ring-opening polymerization of DOL is achieved to form a LiNO3-modified polyDOL-based electrolyte. New mechanism of Li migration in polymer electrolytes have been revealed by molecular dynamics modeling and constructed molecular interface models. It is found that the electrolyte interior is affected by the ion–dipole interactions of Li+ by NO3−, which made it easier for Li+ to be released from the polar ether-oxygen ligands on the polymer chain for rapid migration, thus exhibiting an ionic conductivity of 1.8 mS cm−1 and tLi+ of 0.78. In addition, NO3− preempts the binding sites around Li+, improves the coordination environment, and prioritizes the formation of a kinetically stable anion-derivative interface, which effectively mitigates the interfacial side reactions between the electrodes and the electrolytes. As a result, the assembled solid-state Li||LiFePO4 cell exhibits an impressive 152.3 mAh/g discharge capacity at 0.5C and maintains 80.3 % of the capacity after 450 cycles at 50 °C. This work not only opens a new avenue for designing high-performance gel polymer electrolytes for more metal-based batteries, but also provides valuable insights into understanding the ion migration mechanism.

Synergy of Dendrites-Impeded Atomic Clusters Dissociation and Side Reactions Suppressed Inert Interface Protection for Ultrastable Zn Anode.

The sluggish ions-transfer and inhomogeneous ions-nucleation induce the formation of randomly oriented dendrites on Zn anode, while the chemical instability at anode-electrolyte interface triggers detrimental side reactions. Herein, this report in situ designs a multifunctional hybrid interphase of Bi/Bi2O3, for the first time resulting in a novel synergistic regulation mechanism involving: (i) chemically inert interface protection mechanism suppresses side reactions; and more fantastically, (ii) innovative thermodynamically favorable Zn atomic clusters dissociation mechanism impedes dendrites formation. Assisted by collaborative modulation behavior, the Zn@Bi/Bi2O3 symmetry cell delivers an ultrahigh cumulative plating capacity of 1.88 Ah cm-2 at 5mA cm-2 and ultralong lifetimes of 300h even at high current density and depth of discharge (10mA cm-2, DODZn: 60%). Furthermore, under a low electrolyte-to-capacity ratio (E/C: 45µL mAh-1) and negative-to-positive capacity ratio (N/P: 6.3), Zn@Bi/Bi2O3||MnO2 full-cell exhibits a superior capacity retention of 86.7% after 500 cycles at 1 A g-1, which outperforms most existing interphases. The scaled-up Zn@Bi/Bi2O3||MnO2 battery module (6V, 1 Ah), combined with the photovoltaic panel, presents excellent renewable-energy storage ability and long output lifetime (12h). This work provides a fantastic synergistic mechanism to achieve the ultrastable Zn anode and can be greatly promised to apply it into other metal-based batteries.

Uniform Li Deposition through the Graphene-Based Ion-Flux Regulator for High-Rate Li Metal Batteries.

Lithium (Li) metal is considered an ultimate anode owing to its high specific capacity and energy density. However, uncontrolled Li dendrite growth and low Coulombic efficiency have limited the application of Li metal. Among various strategies introduced to address these limitations, the surface modification of polyolefin separators with functional materials has been widely adopted for improving the mechanical and thermal stabilities of polymer separators and to protect the separator from the penetration of Li dendrites. Herein, we report a new functional polymer separator that is surface-altered with a graphene-based Li-ion flux regulator (GLR) to homogenize the Li-ion flux and suppress the growth of sharp dendritic Li in Li metal batteries. The nanopores distributed through the GLR structure serve as channels for ion transport and junctions for electron transfer, facilitating efficient electrolyte penetration and rapid charge transfer between graphene (Gr) sheets. Owing to these favorable features of porous GLR, a Li-Cu cell with the GLR surface-altered polypropylene separator (GLR-PP) delivers excellent cycle and rate performances compared to a Li-Cu cell with a Gr surface-altered polypropylene separator. In addition, among the tested cells, Li-sulfur cells with GLR-PP exhibit the most stable cycle performance over 500 cycles. These results demonstrate that the concept of tailoring the surface of a polymer separator with porous 2D materials is an effective strategy for improving the long-term cycle stability and electrochemical kinetics of Li metal-based batteries and would trigger further relevant studies.

Solvation structure regulation for an ether/ether biphasic electrolyte to balance cathodic and anodic reactions in metal-based batteries

An ether/ether biphasic liquid electrolyte is constructed via the difference in solvation abilities of ethylene glycol dibutyl ether (EGDE) and tetraglyme (G4) for lithium salt to prevent the shuttle effect of redox mediators (RMs).

A review on instability factors of mono- and divalent metal ion batteries: from fundamentals to approaches

Degradation phenomena in different components (cathode, anode, current collectors (CCs)) of mono- and divalent metal-based batteries affect their performance.

Redistributing zinc-ion flux by work function chemistry toward stabilized and durable Zn metal batteries

A multifunctional NbN-modified separator and an innovative work function chemistry strategy are designed to enhance the durability of ZMBs.

Self-charging aqueous hydrogen gas batteries

Self-charging aqueous hydrogen gas batteries with three different self-charging modes are developed, i.e., chemically self-charging, short-circuit induced self-charging, and low-energy-input triggered quasi-self-charging.

Recent progress in 2D inorganic non-conductive materials for alkali metal-based batteries

The recent progress in the strategies for the preparation of 2D inorganic non-conductive materials and their and application in alkali metal-based batteries is summarized in this review.

A Glass-Interphase for Highly Reversible and Stable RT-Na/S Batteries

Owing to the high theoretical specific capacity (1165 mA h g-1), high natural abundance, and low redox potential (-2.71 V vs standard hydrogen electrode), sodium metal is considered as an ideal anode material for the next-generation high-energy batteries. Though, a high-temperature variant of the sodium-sulfur batteries has already been commercialized, its compromised safety (due to high-temperature operation, 250 – 300 ⁰C) has triggered the research interest in developing its room-temperature analogue. At room-temperature, the thermodynamic instability of Na metal with the liquid electrolytes often leads to develop a thick and chemically unstable interphase, often called the solid electrolyte interphase (SEI). Upon Na plating/stripping, the SEI grows and dissolves repeatedly, results in consuming both the Na anode and the electrolyte inventory. The Na dendrites, the primary unknown risk associated with Na metal-based batteries, are inclined to develop from the fractured sites of the SEI. The SEI exfoliation can be attributed to weak chemical adhesion between the SEI and the Na metal anode. Functional additives, engineered solvents, and the high concentration electrolytes have often been used to alter the mechanical and electrochemical properties of the SEI. It is apparent that, a stable and durable SEI is the key to creating a secure, dendrite-free, and long-lasting RT-Na/S batteries.More recently, the idea of glass-electrolytes to stabilize the metal anodes is disclosed by the Nobel laureate Prof. J. Goodenough. The glass-electrolyte is used to suppress the dendrite growth and ensured improved safety of the high-energy metal-sulfur batteries. However, the cell experiences a huge interfacial resistance due to metal anode/glass-electrolyte interface.The present work relates to the development of a glass-interphase for RT-Na/S batteries. The interphase is grown directly over the sodium metal anode through a simple and scalable approach. To growth the interphase, a novel organic molecule is used to facilitate the formation of the glass-interphase, and called as “glass-interphase forming additive (GIFA). In general, GIFAs contains the hydrolysable group, which is commonly an amine, acyloxy, alkoxy, or halogen on one side, and one Si atom. It contains organo-functional group, such as epoxide, on other side. The presence of oxide or hydroxide is essential in realizing interaction of GIFA with the sodium metal surface.

(Invited) Integration of Sulfide and Halide Based Solid-Electrolyte Membranes with Li-Ion Cathodes

Lithium metal-based batteries (LMBs) employ a Li-metal anode coupled with a conventional high voltage ceramic cathode. The higher capacity of Li vs. graphite (3861 mAh g-1 vs. 372 mAh g-1) combined with high voltage cathodes results in an over 50% increase in the specific energy versus conventional ion-insertion anodes. All-solid-state batteries (ASSBs) can achieve the sought-after high energies when employing cathodes such as LiNi0.8Mn0.1Co0.1O2 (NMC811) and LiNi0.5Mn1.5O4. Having the SEs be as thin as practically possible maximizes the energy density of the cells by both reducing the total weight and achieving voltage window closer to the theoretical limit due to reduced impedance. Likewise, a thin metal anode is sought-after since it reduces the cell weight as well as the risk associated with accidental ignition of the metal. Argyrodite SEs such as Li6PS5Cl (LPSCl) and Li6PS5Br (LPSBr) form terminal decomposition products such as Li3P and Li2S at the metal anode. However, it is the presence of halide-based decomposition products such as LiCl that kinetically stabilizes the interface. For example, substantially improved ASSB performance has been achieved with “sandwich” structures such as LPSCl/LGPS/LPSCl. The talk will focus on the recent approaches to improve interfacial stability of sulfide based solid electrolytes (SEs) with Li-metal and NMC based cathodes for SSB’s. A comparative evaluation of SSB performance between Argyrodite (Li6PS5X, X= Cl, Br) and halide-based SE (Li3ACl6, A = In, Y) using them as a separator and catholyte will be presented. Overall, these results demonstrate that incorporating oxidatively stable SEs in composite cathodes does not necessarily ensure the formation of robust NMC/SE interfaces, and cumulative irreversible capacity losses in such cells can yield rapid performance decline. Rather than SE decomposition, the dominant cause for capacity fade in SSBs is due to active material isolation resulting from repeated volume changes during cycling. Further, additional understanding of the mechanics of solid-solid interfaces and their dynamical evolution during SSB operation will be critical to address key performance bottlenecks for Li metal SSBs.

Comparison of electrochemical lithium and sodium metal deposition: A surface plasmon resonance spectroscopy investigation

Electrochemical deposition of alkali metals on the electrode surface is important for the development of metal-based batteries with high-energy density. Here, we investigate using electrochemical surface plasmon resonance spectroscopy (EC-SPR) to compare the deposition mechanisms of lithium and sodium metal. The SPR spectrum of the Cu film electrode was clearly observed for both LiPF6 and NaPF6 based organic electrolytes. The corresponding SPR spectra for both Li and Na system were dramatically red-shifted at 1st metal deposition process, indicated direct metal deposition on Cu surface. The Li system repeatedly showed similar red shift until at least the 2nd cycle, while similar red shift was not observed at all in the Na system. This indicated that direct Na-metal deposition on the Cu electrode surface was prevented by some passivation film, formed at 1st deposition process. The complex nature of Na-metal deposition, including the surface film phenomena, is responsible for the instability at the interface between the negative electrode and electrolyte in a Na-based battery system. This suggests that Na-based systems need to be more carefully designed and managed than Li-based systems.

Acceleration of interfacial kinetics induced by regulation of Li+ desolvation process in lithium metal-based batteries

Lithium (Li) metal anode is the most promising anode for next-generation high-energy-density batteries due to the high theoretical specific capacity and the lowest redox potential. However, the uncontrollable growth of lithium dendrite and infinite volume expansion limit the development of Li metal-based batteries (LMBs). Introducing functional additives into electrolytes is considered as one of the efficient and economical strategies to suppress the Li dendrite growth and relieve the volume effect. Nevertheless, single-functional electrolyte additives can hardly comprehensively enhance the electrochemical performance of LMBs. Herein, boron-based anion receptor Tris(hexafluoroisopropyl) Borate (THFPB) is introduced into the electrolyte to weaken the interaction between the solvent and lithium ions, which regulates the lithium-ion desolvation process and enhance Li+ migration, resulting in the formation of smooth, dense, and rich-inorganic solid electrolyte interphase (SEI) film. Strikingly, with 2 wt % THFPB additive, the Li||Li cell shows an extremely long cycle life of 4200 h, and the Li||Cu cell affords a high Coulombic efficiency (CE) of 99.87 %. The THFPB-modified electrolyte shows superior universality, which enhances the cycling and rate performance of the Li||S and Li||LiFePO4 cells. Generally, this work provides a new perspective on the selection of new functional additives to achieve a long cycling life Li metal battery with great performance.