Lithium metal has been regarded as the future anode material for high-energy-density rechargeable batteries due to its favorable combination of negative electrochemical potential and high theoretical ...capacity. However, uncontrolled lithium deposition during lithium plating/stripping results in low Coulombic efficiency and severe safety hazards. Herein, we report that nanodiamonds work as an electrolyte additive to co-deposit with lithium ions and produce dendrite-free lithium deposits. First-principles calculations indicate that lithium prefers to adsorb onto nanodiamond surfaces with a low diffusion energy barrier, leading to uniformly deposited lithium arrays. The uniform lithium deposition morphology renders enhanced electrochemical cycling performance. The nanodiamond-modified electrolyte can lead to a stable cycling of lithium | lithium symmetrical cells up to 150 and 200 h at 2.0 and 1.0 mA cm
, respectively. The nanodiamond co-deposition can significantly alter the lithium plating behavior, affording a promising route to suppress lithium dendrite growth in lithium metal-based batteries.Lithium metal is an ideal anode material for rechargeable batteries but suffer from the growth of lithium dendrites and low Coulombic efficiency. Here the authors show that nanodiamonds serve as an electrolyte additive to co-deposit with lithium metal and suppress the formation of dendrites.
Lithium (Li) metal has been considered as an important substitute for the graphite anode to further boost the energy density of Li‐ion batteries. However, Li dendrite growth during Li ...plating/stripping causes safety concern and poor lifespan of Li metal batteries (LMB). Herein, fluoroethylene carbonate (FEC) additives are used to form a LiF‐rich solid electrolyte interphase (SEI). The FEC‐induced SEI layer is compact and stable, and thus beneficial to obtain a uniform morphology of Li deposits. This uniform and dendrite‐free morphology renders a significantly improved Coulombic efficiency of 98% within 100 cycles in a Li | Cu half‐cell. When the FEC‐protected Li metal anode matches a high‐loading LiNi0.5Co0.2Mn0.3O2 (NMC) cathode (12 mg cm−2), a high initial capacity of 154 mAh g−1 (1.9 mAh cm−2) at 180.0 mA g−1 is obtained. This LMB with conversion‐type Li metal anode and intercalation‐type NMC cathode affords an emerging energy storage system to probe the energy chemistry of Li metal protection and demonstrates the material engineering of batteries with very high energy density.
Fluoroethylene carbonate (FEC) additive is used to form a LiF‐rich solid electrolyte interphase (SEI). The FEC‐induced SEI layer is compact and stable, and therefore beneficial to obtain a uniform morphology of Li deposits. When the FEC‐protected Li metal anode matches a high‐loading oxide cathode, a high initial capacity and stable cycling are achieved.
Lithium (Li) metal is the most promising electrode for next‐generation rechargeable batteries. However, the challenges induced by Li dendrites on a working Li metal anode hinder the practical ...applications of Li metal batteries. Herein, nitrogen (N) doped graphene was adopted as the Li plating matrix to regulate Li metal nucleation and suppress dendrite growth. The N‐containing functional groups, such as pyridinic and pyrrolic nitrogen in the N‐doped graphene, are lithiophilic, which guide the metallic Li nucleation causing the metal to distribute uniformly on the anode surface. As a result, the N‐doped graphene modified Li metal anode exhibits a dendrite‐free morphology during repeated Li plating and demonstrates a high Coulombic efficiency of 98 % for near 200 cycles.
The matrix: Nitrogen‐doped graphene is used as the Li plating matrix to regulate Li metal nucleation and suppress dendrite growth. The N‐containing functional groups in the N‐doped graphene are lithiophilic, which guide the Li nucleation and give a uniform distribution of Li on the anode surface. The dendrite‐free lithium‐metal anodes exhibit an impressive electrochemical performance.
High‐energy‐density Li metal batteries suffer from a short lifespan under practical conditions, such as limited lithium, high loading cathode, and lean electrolytes, owing to the absence of ...appropriate solid electrolyte interphase (SEI). Herein, a sustainable SEI was designed rationally by combining fluorinated co‐solvents with sustained‐release additives for practical challenges. The intrinsic uniformity of SEI and the constant supplements of building blocks of SEI jointly afford to sustainable SEI. Specific spatial distributions and abundant heterogeneous grain boundaries of LiF, LiNxOy, and Li2O effectively regulate uniformity of Li deposition. In a Li metal battery with an ultrathin Li anode (33 μm), a high‐loading LiNi0.5Co0.2Mn0.3O2 cathode (4.4 mAh cm−2), and lean electrolytes (6.1 g Ah−1), 83 % of initial capacity retains after 150 cycles. A pouch cell (3.5 Ah) demonstrated a specific energy of 340 Wh kg−1 for 60 cycles with lean electrolytes (2.3 g Ah−1).
A solid electrolyte interphase (SEI) was proposed for practical high‐energy‐density Li batteries. The intrinsic uniformity and the constant supplements of building blocks of SEI jointly afford a sustainable SEI. A pouch cell with a specific energy of 340 Wh kg−1 underwent 60 cycles with a retention of 90 %.
Safe and rechargeable lithium metal batteries have been difficult to achieve because of the formation of lithium dendrites. Herein an emerging electrolyte based on a simple solvation strategy is ...proposed for highly stable lithium metal anodes in both coin and pouch cells. Fluoroethylene carbonate (FEC) and lithium nitrate (LiNO3) were concurrently introduced into an electrolyte, thus altering the solvation sheath of lithium ions, and forming a uniform solid electrolyte interphase (SEI), with an abundance of LiF and LiNxOy on a working lithium metal anode with dendrite‐free lithium deposition. Ultrahigh Coulombic efficiency (99.96 %) and long lifespans (1000 cycles) were achieved when the FEC/LiNO3 electrolyte was applied in working batteries. The solvation chemistry of electrolyte was further explored by molecular dynamics simulations and first‐principles calculations. This work provides insight into understanding the critical role of the solvation of lithium ions in forming the SEI and delivering an effective route to optimize electrolytes for safe lithium metal batteries.
Not dead ′Li′: Fluoroethylene carbonate (FEC) and lithium nitrate (LiNO3) were concurrently introduced into an electrolyte, thus altering the solvation sheath of lithium ions and forming a uniform solid electrolyte interphase (SEI). An abundance of LiF and LiNxOy is formed on the working lithium metal anode and contributes to dendrite‐free lithium deposition.
The lithium metal anode is regarded as a promising candidate in next‐generation energy storage devices. Lithium nitrate (LiNO3) is widely applied as an effective additive in ether electrolyte to ...increase the interfacial stability in batteries containing lithium metal anodes. However, because of its poor solubility LiNO3 is rarely utilized in the high‐voltage window provided by carbonate electrolyte. Dissolution of LiNO3 in carbonate electrolyte is realized through an effective solvation regulation strategy. LiNO3 can be directly dissolved in an ethylene carbonate/diethyl carbonate electrolyte mixture by adding trace amounts of copper fluoride as a dissolution promoter. LiNO3 protects the Li metal anode in a working high‐voltage Li metal battery. When a LiNi0.80Co0.15Al0.05O2 cathode is paired with a Li metal anode, an extraordinary capacity retention of 53 % is achieved after 300 cycles (13 % after 200 cycles for LiNO3‐free electrolyte) and a very high average Coulombic efficiency above 99.5 % is achieved at 0.5 C. The solvation chemistry of LiNO3‐containing carbonate electrolyte may sustain high‐voltage Li metal anodes operating in corrosive carbonate electrolytes.
Liquid assets: LiNO3 can be dissolved directly in an ethylene carbonate/diethyl carbonate electrolyte mixture by adding a trace amount of copper fluoride to promote dissolution. The solvation structure of the electrolyte system protects the lithium metal anode in a working high‐voltage lithium metal battery. NCA=LiNi0.80Co0.15Al0.05O2.
The lithium (Li) metal anode is confronted by severe interfacial issues that strongly hinder its practical deployment. The unstable interfaces directly induce unfavorable low cycling efficiency, ...dendritic Li deposition, and even strong safety concerns. An advanced artificial protective layer with single‐ion pathways holds great promise for enabling a spatially homogeneous ionic and electric field distribution over Li metal surface, therefore well protecting the Li metal anode during long‐term working conditions. Herein, a robust dual‐phase artificial interface is constructed, where not only the single‐ion‐conducting nature, but also high mechanical rigidity and considerable deformability can be fulfilled simultaneously by the rational integration of a garnet Al‐doped Li6.75La3Zr1.75Ta0.25O12‐based bottom layer and a lithiated Nafion top layer. The as‐constructed artificial solid electrolyte interphase is demonstrated to significantly stabilize the repeated cell charging/discharging process via regulating a facile Li‐ion transport and a compact Li plating behavior, hence contributing to a higher coulombic efficiency and a considerably enhanced cyclability of lithium metal batteries. This work highlights the significance of rational manipulation of the interfacial properties of a working Li metal anode and affords fresh insights into achieving dendrite‐free Li deposition behavior in a working battery.
A single‐ion‐conducting interface consisting of dual‐layer architecture is proposed to regulate a homogeneous ionic and electric field distribution while achieving a superior mechanical feature at the surface of a lithium‐metal anode simultaneously, synergistically enabling a highly efficient cell performance of working lithium‐metal batteries.
Lithium metal has been considered as one of the most promising anode materials in high‐energy‐density rechargeable batteries due to its extremely high specific capacity and very low reduction ...potential of all possible candidates. However, the mysterious interfacial phenomena of lithium metal anode in long‐term cycles, especially Li dendrite formation and low Coulombic efficiency, have greatly plagued the practical applications of Li metal in secondary batteries. The complex interface between Li metal and electrolyte plays a very important role in regulating Li deposition and enhancing the cycling stability of a full battery. In this review, recent advances in interfacial science and engineering are summarized to afford a fundamental understanding in Li deposition behavior and present design principles in constructing robust interface to stabilize Li metal anode in a working battery. Further investigations and directions are also included to promote the exploration of Li metal anodes. In particular, the rational combination of different Li metal protection strategies is strongly commended for practically applying Li metal anode in high‐energy‐density rechargeable batteries.
The interfacial science and engineering of Li metal anode and electrolyte are summarized to afford a fundamental understanding in Li deposition behavior and present design principles in constructing robust interface to stabilize Li metal anode in a working battery. The rational combination of different Li metal protection strategies is strongly commended for their practical applications in high‐energy‐density batteries.
Columnar Lithium Metal Anodes Zhang, Xue‐Qiang; Chen, Xiang; Xu, Rui ...
Angewandte Chemie International Edition,
November 6, 2017, Letnik:
56, Številka:
45
Journal Article
Recenzirano
The rechargeable lithium metal anode is of utmost importance for high‐energy‐density batteries. Regulating the deposition/dissolution characteristics of Li metal is critical in both fundamental ...researches and practical applications. In contrast to gray Li deposits featured with dendritic and mossy morphologies, columnar and uniform Li is herein plated on lithium‐fluoride (LiF)‐protected copper (Cu) current collectors. The electrochemical properties strongly depended on the microscale morphologies of deposited Li, which were further embodied as macroscale colors. The as‐obtained ultrathin and columnar Li anodes contributed to stable cycling in working batteries with a dendrite‐free feature. This work deepens the fundamental understanding of the role of LiF in the nucleation/growth of Li and provides emerging approaches to stabilize rechargeable Li metal anodes.
Columnar Li deposition is obtained on uniform and dense nucleation sites formed by regulation of LiF. The obvious relation between microstructure and macroscale color provides an emerging descriptor to judge the uniformity of the deposited Li. Ultrathin and stable Li anodes are further developed to meet the intensive demand for high‐energy‐density batteries.
Lithium (Li) metal is regarded as a “Holy Grail” electrode for next‐generation high‐energy‐density batteries. However, the electrochemical behavior of the Li anode under a practical working state is ...poorly understood, leading to a gap in the design strategy and the aim of efficient Li anodes. The electrochemical diagram to reveal failure mechanisms of ultrathin Li in pouch cells is demonstrated. The working mode of the Li metal anode ranging from 1.0 mA cm−2/1.0 mAh cm−2 (28.0 mA/28.0 mAh) to 10.0 mA cm−2/10.0 mAh cm−2 (280.0 mA/280.0 mAh) is investigated and divided into three categories: polarization, transition, and short‐circuit zones. Powdering and the induced polarization are the main reasons for the failure of the Li electrode at small current density and capacity, while short‐circuit occurs with the damage of the separator leading to safety concerns being dominant at large current and capacity. The electrochemical diagram is attributed from the distinctive plating/stripping behaviors of Li metal, accompanied by dendrites thickening and/or lengthening, and heterogeneous distribution of dendrites. A clear understanding in the electrochemical diagram of ultrathin Li is the primary step to rationally design an effective Li electrode and render a Li metal battery with high energy density, long lifespan, and enhanced safety.
The failure mechanisms of ultrathin lithium in pouch cells can be divided into three categories: polarization, transition, and short‐circuit. A clear working pattern for ultrathin Li metal in pouch cells is established, which can potentially assist in designing a promising strategy for an advanced Li metal anodes.
PDF
