Lithium–Sulfur (Li‒S) battery is regarded as the most promising next-generation energy storage system due to their low cost and high theoretical energy density. However, the formation of dendritic ...morphology of Li makes the side reactions between Li metal anode and lithium polysulfides (LiPSs) more serious, leading to the depletion active materials and short lifespan of batteries, which becomes a bottle neck of their practical application. Herein, a LiF-rich Li deposition regulating layer (LDRL) is developed to protect the Li anode in Li‒S battery. The LiF-rich LDRL can effectively regulate the deposition morphology of Li, thus decreases the corrosion of the LiPSs to the Li anode. A symmetrical cell with LDRL can stably cycle for more than 700 h at a current density of 1 mA cm−2. The Li‒S batteries using Li anodes with a LDRL presents better cycling stability (760 mAh g−1 after 100 cycles at 0.1 C) compared with the batteries using the bare Li anodes. This work provides a new idea for protecting Li anode in Li‒S battery.
Fast charging is considered to be a key requirement for widespread economic success of electric vehicles. Current lithium‐ion batteries (LIBs) offer high energy density enabling sufficient driving ...range, but take considerably longer to recharge than traditional vehicles. Multiple properties of the applied anode, cathode, and electrolyte materials influence the fast‐charging ability of a battery cell. In this review, the physicochemical basics of different material combinations are considered in detail, identifying the transport of lithium inside the electrodes as the crucial rate‐limiting steps for fast‐charging. Lithium diffusion within the active materials inherently slows down the charging process and causes high overpotentials. In addition, concentration polarization by slow lithium‐ion transport within the electrolyte phase in the porous electrodes also limits the charging rate. Both kinetic effects are responsible for lithium plating observed on graphite anodes. Conclusions drawn from potential and concentration profiles within LIB cells are complemented by extensive literature surveys on anode, cathode, and electrolyte materials—including solid‐state batteries. The advantages and disadvantages of typical LIB materials are analyzed, resulting in suggestions for optimum properties on the material and electrode level for fast‐charging applications. Finally, limitations on the cell level are discussed briefly as well.
The limited fast‐charging capabilities of state‐of‐the‐art lithium‐ion batteries hinder market adoption of electric vehicles. In this review, the physicochemical basics influencing fast charging are elucidated and material aspects are analyzed, resulting in lithium transport within the electrodes (active materials and electrolyte therein) as the crucial rate‐limiting process. Thus, ways to improve materials regarding their fast‐charging capabilities are suggested.
The electrolytes in lithium metal batteries have to be compatible with both lithium metal anodes and high voltage cathodes, and can be regulated by manipulating the solvation structure. Herein, to ...enhance the electrolyte stability, lithium nitrate (LiNO3) and 1,1,2,2‐tetrafuoroethyl‐2′,2′,2′‐trifuoroethyl(HFE) are introduced into the high‐concentration sulfolane electrolyte to suppress Li dendrite growth and achieve a high Coulombic efficiency of >99 % for both the Li anode and LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes. Molecular dynamics simulations show that NO3− participates in the solvation sheath of lithium ions enabling more bis(trifluoromethanesulfonyl)imide anion (TFSI−) to coordinate with Li+ ions. Therefore, a robust LiNxOy−LiF‐rich solid electrolyte interface (SEI) is formed on the Li surface, suppressing Li dendrite growth. The LiNO3‐containing sulfolane electrolyte can also support the highly aggressive LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode, delivering a discharge capacity of 190.4 mAh g−1 at 0.5 C for 200 cycles with a capacity retention rate of 99.5 %.
A sulfone‐based electrolyte that contains LiNO3 is developed to support two extreme and aggressive electrodes, the lithium metal anode and the LiNi0.8Mn0.1Co0.1O2 (NMC811) cathode, by forming stable electrode electrolyte interfaces with a high Li plating/stripping Coulombic efficiency of 99.0 % and an unprecedentedly high capacity retention of 99.5 % for the NMC811||Li cells. CEI=cathode electrolyte interphase; SEI=solid electrolyte interface; TFSI−= bis(trifluoromethanesulfonyl)imide anion.
Solid‐state electrolytes are the key to the development of lithium‐based batteries with dramatically improved energy density and safety. Inspired by ionic channels in biological systems, a novel ...class of pseudo solid‐state electrolytes with biomimetic ionic channels is reported herein. This is achieved by complexing the anions of an electrolyte to the open metal sites of metal–organic frameworks (MOFs), which transforms the MOF scaffolds into ionic‐channel analogs with lithium‐ion conduction and low activation energy. This work suggests the emergence of a new class of pseudo solid‐state lithium‐ion conducting electrolytes.
A novel class of lithium‐ion conducting electrolytes by complexing perchlorate anions to the open metal sites of metal–organic frameworks is reported, resulting in negatively charged ionic channels analogous to the ionic channels in biological systems. Such biomimetic ionic channels allow rapid transport of lithium ions with low activation energy.
Lithium metal is among the most promising anode materials in next-generation energy-storage systems. However, Li dendrite growth and unstable solid electrolyte interphase have hindered its practical ...applications. Structured current collectors have been widely proposed to settle these issues, whereas the pre-filling of Li metal into structured anode is challenging. We proposed a coralloid silver-coated carbon fiber-based composite Li anode (CF/Ag-Li) through Ag electroplating and molten Li infusion. The molten Li can be infused into the carbon fiber framework due to the lithiophilic nature of Ag. In addition, a dendrite-free morphology and extraordinary electrochemical performance are achieved in Li-LiFePO4 and Li-sulfur cells. The CF/Ag-Li|Li symmetrical cells can cycle for 160 cycles at 10.0 mA cm−2 and 10.0 mAh cm−2. The CF/Ag-Li|S cells exhibited a high initial discharge capacity of 785 mAh g−1 and a large capacity retention rate after 400 cycles at 0.5C.
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•Coralloid carbon fibers were achieved by electroplating Ag onto their surface•Ag coating layer endows electrodes with lithiophilic nature to syphon molten Li•The composite Li electrode can cycle without dendrite growth or volume change•The composite Li can match Li-containing (LiFePO4) and Li-free (sulfur) cathodes
With the rapid development of electric vehicles and portable electronics such as mobile phones and laptops, the widely used lithium (Li)-ion batteries are having many difficulties in meeting the growing demands for high-energy-density energy-storage systems. Li metal, with an ultrahigh theoretical specific capacity of 3,860 mAh g−1 and the lowest negative electrochemical potential (−3.040 V versus standard hydrogen electrode), has become one of the most promising anode materials for next-generation batteries. Unfortunately, the practical application of Li metal anode has been hindered by its low cycling efficiency, short lifespan, and potential safety hazards. Herein we propose a Li-containing composite electrode based on coralloid carbon fibers that exhibited extraordinary electrochemical performance in full cells of Li-S and Li-LiFePO4 batteries. Such proof of concept on Li-infused structured electrodes sheds fresh light on the dendrite-free plating of Li metal anodes in working rechargeable batteries.
Lithium (Li) metal is among the most promising anode materials for next-generation high-energy-density batteries. However, both dendrite growth and unstable solid electrolyte interphases have hindered its practical applications. Herein, we propose a coralloid carbon fiber-based composite lithium anode, which is an initially Li-containing structured anode. Such electrode design renders dendrite-free morphology during repeated stripping/plating cycles and extraordinary electrochemical performance in Li-LiFePO4 and Li-sulfur cells.
Li‐ion and Li–S batteries find enormous applications in different fields, such as electric vehicles and portable electronics. A separator is an indispensable part of the battery design, which ...functions as a physical barrier for the electrode as well as an electrolyte reservoir for ionic transport. The properties of the separators directly influence the performance of the batteries. Traditional polyolefin separators showed low thermal stability, poor wettability toward the electrolyte, and inadequate barrier properties to polysulfides. To improve the performance and durability of Li‐ion and Li–S batteries, development of advanced separators is required. In this review, we summarize recent progress on the fabrication and application of novel separators, including the functionalized polyolefin separator, polymeric separator, and ceramic separator, for Li‐ion and Li–S batteries. The characteristics, advantages, and limitations of these separators are discussed. A brief outlook for the future directions of the research in the separators is also provided.
Engineering the separator: Traditional polyolefin separators used for Li‐ion and Li–S batteries have inherent limitations, such as low wettability toward electrolyte and poor barrier properties. This review summarizes recent efforts in the development of high performance alternative separators. An outlook for the further development of high performance separators is provided.
Lithium metal is recognized as one of the most promising anode materials owing to its ultrahigh theoretical specific capacity and low electrochemical potential. Nonetheless, dendritic Li growth has ...dramatically hindered the practical applications of Li metal anodes. Realizing spherical Li deposition is an effective approach to avoid Li dendrite growth, but the mechanism of spherical deposition is unknown. Herein, a diffusion‐reaction competition mechanism is proposed to reveal the rationale of different Li deposition morphologies. By controlling the rate‐determining step (diffusion or reaction) of Li deposition, various Li deposition scenarios are realized, in which the diffusion‐controlled process tends to lead to dendritic Li deposition while the reaction‐controlled process leads to spherical Li deposition. This study sheds fresh light on the dendrite‐free Li metal anode and guides to achieve safe batteries to benefit future wireless and fossil‐fuel‐free world.
Sphere factor: A diffusion–reaction competition mechanism reveals the principle of spherical Li deposition. By controlling the rate‐determining step of Li deposition, different Li deposition scenarios are revealed, in which the diffusion‐controlled process tends to give dendritic Li deposition while the reaction‐controlled process leads to spherical Li deposition.
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