Stable Cycle Life Research Articles

Engineering Electrolytes with Transition Metal Ions for the Rapid Sulfur Redox and In Situ Solidification of Polysulfides in Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries have been pursued due to their high theoretical energy density and superb cost-effectiveness. However, the dissolution-conversion mechanism of sulfur inevitably leads to shuttle effects and interface passivation issues, which impede Li-S battery practical application. Herein, the approach of adopting transition metal salts (CoI2) to engineering the electrolyte is proposed. Different from anchored transition metal catalysts in the cathode, soluble cobalt ions can chemically reduce and solidify polysulfides, alleviating the dependence of sulfur conversion on the conductive interface while suppressing the shuttle effect. Importantly, all elements in CoI2 are in the lowest valence state and solid complexes are formed after the redox reaction, which prevents the migration of high valent Co3+ to the anode, thus overcoming the poor compatibility between redox mediator and Li anode. Notably, I3- has the function of eliminating dead sulfur and dead lithium, which we apply to Li-S batteries. After activating I3- at a certain frequency, Li-S batteries indeed achieve a longer and more stable cycle life. By combining the regulatory behavior of anions and cations, the electrolyte is engineered for Li-S batteries with high capacity, long lifespan, and excellent rate performance.

Robust polymer electrolytes with fast ion-transport nanochannels constructed by carbon dots for long lifespan Li metal batteries

As an anode material in energy storage systems, Li metal has exceptional merits, including high specific capacity, low density, and low redox potential. However, challenges such as lithium dendrites and unstable solid electrolyte interphase (SEI) hinder the practical application of lithium metal batteries (LMBs). Solid polymer electrolytes (SPEs), notably PVDF-HFP, are expected to overcome the above problems because of their mechanical merits and safe features, but their limited ion transportation behaviors result in insufficient ionic conductivity at room temperature. Herein, we invent an approach to prepare high performance electrolytes composed by porous PVDF-HFP and functionalized carbon dots (CDs). Such porous PVDF-HFP polymer membranes are created by a subtle phase inversion process, possessing a sponge-like structure, vertical lithium-ion transport channels and CDs decorated surfaces, thus able to uptake the liquid electrolyte (LE) to form gel polymer electrolytes (GPEs). The CDs fillers are produced in large scale with adjustable surface states, which can enhance Li salts disassociation to release free Li ions. As a result, the optimal conductivity of the as-prepared GPEs at room temperature is up to 8.7 mS cm−1 and the lithium transference number reaches 0.64. Our GPEs endow Li symmetric batteries with very stable SEI and long cycling life over 2200 h, and help realize high capacities and retention rates of the LMBs using LiFePO4(LFP) or LiCoO2(LCO) cathodes.

Achieving the dendrite-free zinc anode by constructing a Sn-C interfacial layer with zincophilic and conductive network

Under the basic national policy of sustainable green development, high-performance and low-cost energy storage devices are urgently needed for intermittent generation of clean energy and storage of electrical energy. Zn metal with high capacity, abundant reserves and excellent plasticity, but the inevitable side reactions (hydrogen precipitation and corrosion, etc.) of the Zn metal anode itself have severely limited the development of aqueous Zn ion batteries (AZIBs) in the market. In this study, an artificial protective layer of polymer-derived carbon material combined with Sn is prepared to inhibit hydrogen precipitation and corrosion and prolong the lifetime of AZIBs. With these advantages, the Zn@Sn@N doped carbon (Zn@CNS) symmetric cell could achieve a stable cycle life of 1000 h at 2 mA cm-2 and low overpotential. The excellent stripping life of over 400 h is achieved in half-cells assembled with Cu foils. Furthermore, the α-MnO2//Zn@CNS full battery shows superior stability in rate capability and long-term capacity retention compared to the α-MnO2//Zn battery, indicating that the CNS coating provides excellent performance and practical value.

Facile Electrodeposition Method for Constructing Li2S as Artificial Solid Electrolyte Interphase for High-Performance Li Metal Anode.

Designing current collectors and constructing efficient artificial solid electrolyte interphase (SEI) layers are promising strategies for achieving dendrite-free Li deposition and practical applications in Li metal batteries (LMBs). Electrodeposition is advantageous for large-scale production and allows the direct formation of current collectors without binders, making them immediately usable as electrodes. In this study, an adherent Cu2S thin-layer on Cu foil is synthesized through anodic electrodeposition from a Na2S solution in a one-step process, followed by the generation of Li2S layers as artificial SEI layers via a conversion reaction (3DLi2S-Cu foil). The Li2S layers move from the 3D Cu surface to the deposited Li surface, facilitating uniform and dense Li deposition. The 3DLi2S-Cu foil structure demonstrates stable cycling performance over 350 cycles in an asymmetric cell, with a capacity of 1 mAh cm-2 at 1 mA cm-2. Moreover, symmetric cells with 5 mAh cm-2 of deposited Li exhibit a stable cycle life for over 1200 h. When paired with commercial LiFePO4 (LFP), the full cells show substantially enhanced cyclability, regardless of the amount of deposited Li. This study provides new insights into the construction of artificial SEIs for facilitating commercial applications.

Reviving Multivalent‐Metal Anodes in Simple Salt Electrolytes via Component Modifier Design

AbstractUsing combinatory electrolyte blends represents an imperative avenue to achieve good magnesium (Mg)‐metal anode compatibility and commercial feasibility in fields of promising rechargeable Mg batteries. However, fundamental challenges of how to manipulate component modifier reactivity on molecule level still remain to be solved. Here, molecular structure design concepts towards seeking bromophenyl complex‐based component modifiers has been proposed according to implications of electron‐donating and/or electron‐withdrawing substituents on Br−C bond dissociation reactivity. Exceptional Mg electro‐plating/stripping properties (a stable cycle life of 250 days in Mg//Cu asymmetric cells) have been firstly achieved in a simple salt electrolyte with 1‐(3‐bromophenyl)‐N,N‐dimethylmethanamine (BPDMA) as optimal component modifier. Comprehensive analyses disclose the unique electrochemically‐active Br‐containing ion‐pairs formation, such as [(Mg2+)2(TFSI−)Br−]2+ and [(Mg2+)2(TFSI−)(Br−)(G2)2]2+, which results in the much thinner Br− containing and organic–inorganic mixed interphases on Mg‐metal anodes. Furthermore, conventional MgSO4‐based electrolytes and even calcium (Ca)‐ion electrolytes can also be revived by similar strategy, demonstrating its generality and superiority.

Metal‐Organic Framework Hosted Silicon for Long‐Cycling, Low‐Cost, and Flexible Batteries

AbstractDeveloping biodegradable electrodes is a significant step toward environmental sustainability and cost reduction in battery technology. This paper presents a new approach that utilizes metal‐organic framework (MOF)‐encapsulated silicon nanoparticles (SiNPs) as the active anode material within a cellulose‐based electrode. The electrode is free‐standing, flexible, biodegradable, and significantly reduces the strain experienced by SiNPs during volume expansion, resulting in improved capacity and cycle life stability of SiNPs. The high porosity of the electrode creates efficient lithium (Li+) ion transport channels and enhances electrolyte absorption, thus promoting effective contact between the electrolyte and active material. The outcome is rapid electrode kinetics and a highly reversible discharge capacity of 1744.6 mAh g−1 at 0.5 A g−1 versus Li/Li+ over 1000 cycles. Further, full cell tests are conducted that demonstrate a stable cycle performance exceeding 3400 cycles, with an initial discharge capacity retention of 80.5% at 0.5 A g−1. By employing cellulose and avoiding toxic organic solvents and binders, the proposed approach is promising for a substantial reduction of the production costs of Li‐ion batteries. The scalability of the proposed method further enhances its practical viability, offering intriguing economic implications for the future of battery technology.

In Situ Alloying Enabled by Active Liquid Metal Filler for Self‐Healing Composite Polymer Electrolytes

AbstractSolid inorganics, known for kinetically inhibiting polymer crystallization and enhancing ionic conductivity, have attracted significant attention in solid polymer electrolytes. However, current composite polymer electrolytes (CPEs) are still facing challenges in Li metal batteries, falling short of inhibiting severe dendritic growth and resulting in very limited cycling life. This study introduces Ga62.5In21.5Sn16 (Galinstan) liquid metal (LM) as an active liquid alternative to conventional passive solid fillers, aiming at realizing self‐healing protection against dendrite problems. Compared to solid inorganics, for example silica, LM droplets could more significantly reduce polymer crystallinity and enhance Li‐ion conductivity due to their liquid nature, especially at temperatures below the polymer melting point. More importantly, LMs are unraveled as dynamic chemical traps, which are capable of blocking and consuming lithium dendrites upon contact via in situ alloying during battery operation and further inhibiting dendritic growth due to the lower deposition energy barrier of the formed Li‐LM alloy. As a proof of concept, by strategically designing an asymmetric CPE with the active LM filling, a solid‐state Li/LiFePO4 battery achieves promising full‐cell functionality with notable rate performance and stable cycle life. This active filler‐mediated self‐healing approach could bring new insights into the battery design in versatile solid‐state systems.

In Situ Alloying Enabled by Active Liquid Metal Filler for Self-Healing Composite Polymer Electrolytes.

Solid inorganics, known for kinetically inhibiting polymer crystallization and enhancing ionic conductivity, have attracted significant attention in solid polymer electrolytes. However, current composite polymer electrolytes (CPEs) are still facing challenges in Li metal batteries, falling short of inhibiting severe dendritic growth and resulting in very limited cycling life. This study introduces Ga62.5In21.5Sn16 (Galinstan) liquid metal (LM) as an active liquid alternative to conventional passive solid fillers, aiming at realizing self-healing protection against dendrite problems. Compared to solid inorganics, for example silica, LM droplets could more significantly reduce polymer crystallinity and enhance Li-ion conductivity due to their liquid nature, especially at temperatures below the polymer melting point. More importantly, LMs are unraveled as dynamic chemical traps, which are capable of blocking and consuming lithium dendrites upon contact via in situ alloying during battery operation and further inhibiting dendritic growth due to the lower deposition energy barrier of the formed Li-LM alloy. As a proof of concept, by strategically designing an asymmetric CPE with the active LM filling, a solid-state Li/LiFePO4 battery achieves promising full-cell functionality with notable rate performance and stable cycle life. This active filler-mediated self-healing approach could bring new insights into the battery design in versatile solid-state systems.

Hydrogel Electrolyte with Regulated Water Activity and Hydrogen Bond Network for Ultra‐Stable Zinc Electrode

AbstractQuasi‐solid‐state zinc‐ion batteries (QZIBs) have attracted wide attention due to their excellent dimensional stability and high safety. However, poor ion conduction capabilities, severe dendrite growth, and rampant side reactions still hinder their commercialization. The regulation of the solvation structure of Zn2+ is considered to be an effective method to address these issues. Herein, a hydrogel electrolyte with a regulated solvation structure (HE‐RS) is designed via the combination of tetramethyl urea (TMU) additive and polyvinyl alcohol (PVA) matrix. The hydrophilic ─C═O group of TMU exhibits strong affinity with the PVA chains, improving the mechanical strength of the PVA matrix. The ─N(CH3)2 groups at both ends of TMU exhibit strong hydrophobic characteristics, which leads to local hydrophobicity and decreased water activity. Additionally, abundant oxygen‐containing (electronegative) groups on both PVA and TUM can adsorb Zn2+ and provide sites for Zn2+ transference. Benefiting from these merits, Zn2+ solvation structure and deposition behavior are regulated. Consequently, the Zn||Zn symmetric cell with HE‐RS exhibits a stable cycling life exceeding 2000 h. Moreover, the HE‐RS‐based Zn||NH4V4O10 cell exhibits a capacity retention of 96.4% after 1000 cycles at 2 A g−1.

Cationic and Anionic Dual Redox Activity of MoS2 for Electrochemical Potassium Storage.

MoS2 is regarded as one of the most promising potassium-ion battery (PIB) anodes. Despite the great progress to enhance its electrochemical performance, understanding of the electrochemical mechanism to store K-ions in MoS2 remains unclear. This work reports that the K storage process in MoS2 follows a complex reaction pathway involving the conversion reactions of Mo and S, showing both cationic redox activity of Mo and anionic redox activity of S. The presence of dual redox activity, characterized in-depth through synchrotron X-ray absorption, X-ray photoelectron, Raman, and UV-vis spectroscopies, reveals that the irreversible Mo oxidation during the depotassiation process directs the reaction pathway toward S oxidation, which leads to the occurrence of K-S electrochemistry in the (de)potassiation process. Moreover, the dual reaction pathway can be adjusted by controlling the discharge depth at different cycling stages of MoS2, realizing a long-term stable cycle life of MoS2 as a PIB anode.

High-Entropy-Inspired Multicomponent Electrical Double Layer Structure Design for Stable Zinc Metal Anodes.

Regulating the electrical double layer (EDL) structure can enhance the cycling stability of Zn metal anodes, however, the effectiveness of this strategy is significantly limited by individual additives. Inspired by the high-entropy (HE) concept, we developed a multicomponent (MC) EDL structure composed of La3+, Cl-, and BBI anions by adding dibenzenesulfonimide (BBI) and LaCl3 additives into ZnSO4 electrolytes (BBI/LaCl3/ZnSO4). Specifically, La3+ ions accumulate within EDL to shield the net charges on the Zn surface, allowing more BBI anions and Cl- ions to enter this region. Consequently, this unique MC EDL enables Zn anodes to simultaneously achieve uniform electric field, robust SEI layer, and balanced reaction kinetics. Moreover, the synergistic parameter - a novel descriptor for quantifying collaborative improvement - was first proposed to demonstrates the synergistic effect between BBI and LaCl3 additives. Benefitting from these advantages, Zn metal anodes achieved a high reversibility of 99.5 % at a depth of discharge (DoD) of 51.3 %, and Zn|MnO2 pouch cells exhibited a stable cycle life of 100 cycles at a low N/P ratio of 2.9.

Laser-Induced Solid-Phase Strategy to Synthesize Single-Atomic Lithiophilic Sites Enabled Dendrite-Free Lithium Deposition on Graphene Matrix.

The introduction of metal Single-atom (SA) to construct lithium-philic active sites shows the ability to guide uniform lithium deposition and improve the stability of lithium hosts. Nevertheless, the development of facile and expedient methods for synthesizing SA remains a considerable challenge. Herein, The SA metal loaded on graphene (Bi@LrGO) is designed by laser-induced solid-phase strategy. The bismuth salts simultaneously decompose under the high local temperature and in the reductive atmosphere induced by laser to form SA metal. Simultaneously, graphene oxide (GO) nanosheets absorb photon energy to be reduced/graphitized into graphene, which serves as anchoring sites for Bismuth Sing-atom (Bi SA) immobilization. The SA metals, supported on the graphene not only provide sufficient lithiophilic sites but also significantly increase the adsorption energy (-2.11eV) with lithium atoms, promote the uniform nucleation and deposition of lithium, and inhibit the growth of lithium dendrites. Additionally, the layered structure of the graphene film adapts to the volume change during the repeated lithium plating/stripping process. Therefore, the symmetrical battery-based Li deposited on Bi@LrGO (Bi@LrGO@Li) achieves an ultra-long stable cycle life of ≈2400h at 1mAcm-2. In particular, a full cell with LiFePO4 cathode provides a good capacity retention of 81.2% at 4C after 600 cycles.

High‐Entropy‐Inspired Multicomponent Electrical Double Layer Structure Design for Stable Zinc Metal Anodes

AbstractRegulating the electrical double layer (EDL) structure can enhance the cycling stability of Zn metal anodes, however, the effectiveness of this strategy is significantly limited by individual additives. Inspired by the high‐entropy (HE) concept, we developed a multicomponent (MC) EDL structure composed of La3+, Cl−, and BBI anions by adding dibenzenesulfonimide (BBI) and LaCl3 additives into ZnSO4 electrolytes (BBI/LaCl3/ZnSO4). Specifically, La3+ ions accumulate within EDL to shield the net charges on the Zn surface, allowing more BBI anions and Cl− ions to enter this region. Consequently, this unique MC EDL enables Zn anodes to simultaneously achieve uniform electric field, robust SEI layer, and balanced reaction kinetics. Moreover, the synergistic parameter – a novel descriptor for quantifying collaborative improvement – was first proposed to demonstrates the synergistic effect between BBI and LaCl3 additives. Benefitting from these advantages, Zn metal anodes achieved a high reversibility of 99.5 % at a depth of discharge (DoD) of 51.3 %, and Zn|MnO2 pouch cells exhibited a stable cycle life of 100 cycles at a low N/P ratio of 2.9.

Construction of iodine-rich solid electrolyte interphase to achieve highly stable aqueous zinc-ion batteries

Aqueous zinc ion batteries (AZIBs) are considered highly potential secondary energy storage equipment for their higher energy density, lower risk, and affordability. However, parasitic reactions within the anode affect the Zn2+ deposition behavior with uncontrollable dendrite formation significantly shortening the battery lifetime. For improvement of the Zn anode cycling stability, tetraethylammonium iodide (TEAI), a multifunctional additive was introduced into ZnSO4, which constructs an iodine-rich solid electrolyte interphase (SEI) on the zinc anode surface and significantly inhibits the parasitic reactions and nucleation of zinc dendrites. Furthermore, the TEAI also reshapes the solvation sheath of Zn2+, contributing to better transportation kinetics of zinc ions. Attributing to these functions, highly stable AZIBs are realized with the addition of TEAI, in which a stable cycling life of over 3500 h was achieved for symmetric Zn//Zn batteries under 1 mA cm-2. With higher current densities, the battery also exhibited excellent cycling stability over 3500 h. Full cells with the V2O5 cathode were fabricated to examine the commercial availability of TEAI additives, achieving a high reversible discharge capacity of 381 mAh g-1, and the capacity of 102 mAh g-1 was still maintained after 800 cycles at 1 A g-1.

Three-dimensional porous structure CoP/N-doped carbon nanospheres as anode for enhanced lithium storage performance

Transition metal phosphides (TMPs) with high theoretical capacities and safe operating voltage are recognized as prospective anode materials for lithium-ion batteries (LIBs). While, the huge volume expansion and low conductivity of TMPs still restrict their applications. Engineering nanostructured composites consisting of TMPs and conductive carbon-based materials is of great importance to improve electrochemical performance. Herein, a novel and facile pyrolysis-oxidation-phosphidation approach is designed to fabricate porous nanospheres composing of CoP nanoparticles and N-doped carbon substrate. The abundant pores in CoP/N-C provide ample active sites for lithium storage and facilitate Li+ transport. The introduction of N-doped carbon substrate enhances the electrical conductivity, allowing CoP to maintain its structure during cycling. The CoP/N-C anode achieves remarkable cycle performance, maintaining an extremely stable cycle life over 2000 cycles at 5 A g−1. More importantly, the full cell consisting of CoP/N-C and LiFePO4 also exhibits a prominent cycling durability with a capacity retention of 96.5 % at 0.1 A g−1 after 150 cycles. This work proposes a simple and feasible structural engineering strategy, which can provide a new way for optimizing the electrochemical performance of conversion-type anode materials.

La/Ce-doping spherical α-Ni(OH)2 with high discharge capacity and long cycling durability for nickel metal hydride batteries

The currently used β-Ni(OH)2 for alkaline nickel batteries are falling short of higher capacity demand. In contrast, α-Ni(OH)2 with high theoretical capacity can address this need. However, the α-Ni(OH)2 suffers from poor stability and intrinsic low electrical conductivity. Herein, we designed La/Ce-doped spherical α-Ni(OH)2 and study the effect of La/Ce on the structure and electrochemical properties of α-Ni(OH)2. The increased specific surface area of the α-Ni(OH)2 with La/Ce doping reduces the electron transfer resistance. The La/Ce-doped α-Ni(OH)2 with 2 at% La (Ni-La-2) and 3 at% Ce (Ni-Ce-3) doping deliver high capacities of ∼365 mAh g–1 and ∼373 mAh g–1, respectively, which is only 309 mAh g–1 for the pure α-Ni(OH)2. Meanwhile, the La/Ce-doping stabilizes the structural robustness of the α-Ni(OH)2 during cycling. Notably, Ni-La-2 shows a superior stable cycling life with a capacity retention of ∼95 % after 400 cycles, which is ∼20 % higher than that of pure α-Ni(OH)2.

3D self-supporting core-shell silicon-carbon nanofibers-based host enables confined Li+ deposition for lithium metal battery

Three-dimensional (3D) porous hosts play pivotal roles in realizing dendrite-free lithium metal anodes (LMAs) owing to their high specific area. However, uneven local electric field and lack of lithiophilic sites on the reactive interface cause nonuniform lithium ion (Li+) deposition, leading to Li dendrite growth and parasitic reactions. These issues will inevitably incur short cycling life and severe safety hazards of lithium metal batteries. Herein, a 3D self-supporting host composed of hollow carbon nanofibers incorporated with silicon (Si) nanoparticles inside (Si-HCF) is constructed as Li metal host by a scalable coaxial electrospinning technique. During the first cycle, the Si nanoparticles is alloyed with Li+ to form lithiophilic Li-Si alloy, contributing to deliver a low nucleation overpotential and homogeneous surface potential confirmed by Kelvin probe force microscopy, finally guiding Li+ flux homogeneously throughout the fibrous mat. As expected, the Li metal can percolate through Si-HCF host reversibly without uncontrollable Li dendrites and the Si-HCF exhibits a stable cycle life of Li plating/stripping over 1400 h. Additionally, the full cell combined with LiFePO4 cathodes presents steady cycling over 400 cycles with a high average coulombic efficiency of 99.4 %. This work provides new insights for the synthesis of 3D hosts with controllable nucleation sites to homogenize Li+ deposition in LMAs.

Hydrogen‐Bonded Organic Frameworks‐based Electrolytes with Controllable Hydrogen Bonding Networks for Solid‐State Lithium Batteries

AbstractThe lack of stable solid‐state electrolytes (SSEs) with high‐ionic conductivity and the rational design of electrode/electrolyte interfaces remains challenging for solid‐state lithium batteries. Here, for the first time, a high‐performance solid‐state lithium‐oxygen (Li−O2) battery is developed based on the Li‐ion‐conducted hydrogen‐bonded organic framework (LHOF) electrolyte and the HOF‐DAT@CNT composite cathode. Benefiting from the abundant dynamic hydrogen bonding network in the backbone of LHOF‐DAT SSEs, fast Li+ ion transport (2.2×10−4 S cm−1), a high Li+ transference number (0.88), and a wide electrochemical window of 5.05 V are achieved. Symmetric batteries constructed with LHOF‐DAT SSEs exhibit a stably cycled duration of over 1400 h with uniform deposition, which mainly stems from the jumping sites that promote a uniformly high rate of Li+ flux and the hydrogen‐bonding network structure that can relieve the structural changes during Li+ transport. LHOF‐DAT SSEs‐based Li−O2 batteries exhibit high specific capacity (10335 mAh g−1), and stable cycling life up to 150 cycles. Moreover, the solid‐state lithium metal battery with LHOF‐DAT SSEs endow good rate capability (129.6 mAh g−1 at 0.5 C), long‐term discharge/charge stability (210 cycles). The design of LHOF‐DAT SSEs opens an avenue for the development of novel SSEs‐based solid‐state lithium batteries.

Highly Tough Slide‐Crosslinked Gel Polymer Electrolyte for Stable Lithium Metal Batteries

AbstractGel polymer electrolytes (GPEs) hold great promise for the practical application of lithium metal batteries. However, conventional GPEs hardly resists lithium dendrites growth and maintains long‐term cycling stability of the battery due to its poor mechanical performance. Inspired by the slide‐ring structure of polyrotaxanes (PRs), herein we developed a dynamic slide‐crosslinked gel polymer electrolyte (SCGPE) with extraordinary stretchability of 970.93 % and mechanical strength of 1.15 MPa, which is helpful to buffer the volume change of electrodes and maintain mechanical integrity of the battery structure during cycling. Notably, the PRs structures can provide fast ion transport channels to obtain high ionic conductivity of 1.73×10−3 S cm−1 at 30 °C. Additionally, the strong polar groups in SCGPE restrict the free movement of anions to achieve high lithium‐ion transference number of 0.71, which is favorable to enhance Li+ transport dynamics and induce uniform Li+ deposition. Benefiting from these features, the constructed Li|SCGPE‐3|LFP cells exhibit ultra‐long and stable cycle life over 1000 cycles and high‐capacity retention (89.6 % after 1000 cycles). Even at a high rate of 16 C, the cells deliver a high capacity of 79.2 mAh g−1. The slide‐crosslinking strategy in this work provides a new perspective on the design of advanced GPEs for LMBs.

Reviving Multivalent-Metal Anodes in Simple Salt Electrolytes via Component Modifier Design.

Using combinatory electrolyte blends represents an imperative avenue to achieve good magnesium (Mg)-metal anode compatibility and commercial feasibility in fields of promising rechargeable Mg batteries. However, fundamental challenges of how to manipulate component modifier reactivity on molecule level still remain to be solved. Here, molecular structure design concepts towards seeking bromophenyl complex-based component modifiers has been proposed according to implications of electron-donating and/or electron-withdrawing substituents on Br-C bond dissociation reactivity. Exceptional Mg electro-plating/stripping properties (a stable cycle life of 250 days in Mg//Cu asymmetric cells) have been firstly achieved in a simple salt electrolyte with 1-(3-bromophenyl)-N,N-dimethylmethanamine (BPDMA) as optimal component modifier. Comprehensive analyses disclose the unique electrochemically-active Br-containing ion-pairs formation, such as [(Mg2+)2(TFSI-)Br-]2+ and [(Mg2+)2(TFSI-)(Br-)(G2)2]2+, which results in the much thinner Br- containing and organic-inorganic mixed interphases on Mg-metal anodes. Furthermore, conventional MgSO4-based electrolytes and even calcium (Ca)-ion electrolytes can also be revived by similar strategy, demonstrating its generality and superiority.