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.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
All‐solid‐state Li metal batteries have attracted extensive attention due to their high safety and high energy density. However, Li dendrite growth in solid‐state electrolytes (SSEs) still hinders ...their application. Current efforts mainly aim to reduce the interfacial resistance, neglecting the intrinsic dendrite‐suppression capability of SSEs. Herein, the mechanism for the formation of Li dendrites is investigated, and Li‐dendrite‐free SSE criteria are reported. To achieve a high dendrite‐suppression capability, SSEs should be thermodynamically stable with a high interface energy against Li, and they should have a low electronic conductivity and a high ionic conductivity. A cold‐pressed Li3N–LiF composite is used to validate the Li‐dendrite‐free design criteria, where the highly ionic conductive Li3N reduces the Li plating/stripping overpotential, and LiF with high interface energy suppresses dendrites by enhancing the nucleation energy and suppressing the Li penetration into the SSEs. The Li3N–LiF layer coating on Li3PS4 SSE achieves a record‐high critical current of >6 mA cm−2 even at a high capacity of 6.0 mAh cm−2. The Coulombic efficiency also reaches a record 99% in 150 cycles. The Li3N–LiF/Li3PS4 SSE enables LiCoO2 cathodes to achieve 101.6 mAh g−1 for 50 cycles. The design principle opens a new opportunity to develop high‐energy all‐solid‐state Li metal batteries.
According to the proposed principles for the suppression of dendrite formation, a Li3N–LiF composite that is thermodynamically stable and has high interface energy against Li metal is designed as an interlayer for dendrite‐free all‐solid‐state batteries. A Li3N–LiF layer coating on a Li3PS4 solid‐state electrolyte achieves a record‐high critical current of >6 mA cm−2 even at a high capacity of 6.0 mAh cm−2.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lithium-ion batteries raise safety, environmental, and cost concerns, which mostly arise from their nonaqueous electrolytes. The use of aqueous alternatives is limited by their narrow electrochemical ...stability window (1.23 volts), which sets an intrinsic limit on the practical voltage and energy output. We report a highly concentrated aqueous electrolyte whose window was expanded to ~3.0 volts with the formation of an electrode-electrolyte interphase. A full lithium-ion battery of 2.3 volts using such an aqueous electrolyte was demonstrated to cycle up to 1000 times, with nearly 100% coulombic efficiency at both low (0.15 coulomb) and high (4.5 coulombs) discharge and charge rates.
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BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
All-solid-state lithium batteries (ASSLIBs) employing sulfide solid electrolyte hold high promise to replace traditional liquid-electrolyte LIBs due to their high safety and energy density. However, ...Li dendritic growth in sulfide electrolyte limits the realization of the high energy of ASSLIBs. In this work, we use LiF (or LiI) layer at the interface between Li and sulfide electrolyte and penetrated HFE (or I solution) inside of sulfide electrolyte to suppress the Li dendrite growth. Due to the higher interface energy of LiF/Li than that of LiI/Li, LiF interlayer show much higher capability than LiI in suppressing the Li dendrite. Even if the Li dendrite breaks through LiF (or LiI) interlayer, the Li dendrites will be consumed by coated/penetrated HEF (or I) forming LiF (or LiI) thus preventing Li dendrite growth. A LiNbO3 @LiCoO2/Li7P3S11/Li ASSLIB employing HFE coated/infiltrated Li7P3S11 glass-ceramic as electrolyte, and LiF coated Li metal as anode shows a high reversible discharge capacity of 118.9 mAh g−1 at 0.1 mA cm−2 and retains 96.8 mAh g−1 after 100 cycles. The designed solid electrolyte interphase between Li and solid electrolyte that has a high interface energy to Li provides new opportunity to commercialize the Li metal batteries.
We demonstrate that a uniform the LiF (or LiI) interfacial layer at Li/Li7P3S11 interface and infiltration of HFE (or I solution) into sulfide electrolyte can suppress the Li dendrite growth. Due to the modification, the assembled Li@LiF/Li7P3S11/LiF@Li symmetrical cell can stably plating/stripping at 0.5 mA cm−2 and 0.1 mAh cm−2 at 25 °C for over 200 cycles. Coupled with the LNO-LCO cathode, the all-solid-state Li@LiF/Li7P3S11/LNO@LCO full cell exhibits a high initial reversible capacity of 118.9 mAh g−1 with excellent cycling stability and high rate performances at room temperature. Display omitted
•Rational coating of LiF (or LiI) on Li enables stable interface.•Infiltrating HFE (or I) into electrolytes suppresses the growth of Li dendrites.•High interface energy of LiF/Li promotes a uniform Li deposition.•High electrochemical performance was achieved for the cell with Li@LiF and HFE.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Metallic zinc (Zn) has been regarded as an ideal anode material for aqueous batteries because of its high theoretical capacity (820 mA h g
), low potential (-0.762 V versus the standard hydrogen ...electrode), high abundance, low toxicity and intrinsic safety. However, aqueous Zn chemistry persistently suffers from irreversibility issues, as exemplified by its low coulombic efficiency (CE) and dendrite growth during plating/ stripping, and sustained water consumption. In this work, we demonstrate that an aqueous electrolyte based on Zn and lithium salts at high concentrations is a very effective way to address these issues. This unique electrolyte not only enables dendrite-free Zn plating/stripping at nearly 100% CE, but also retains water in the open atmosphere, which makes hermetic cell configurations optional. These merits bring unprecedented flexibility and reversibility to Zn batteries using either LiMn
O
or O
cathodes-the former deliver 180 W h kg
while retaining 80% capacity for >4,000 cycles, and the latter deliver 300 W h kg
(1,000 W h kg
based on the cathode) for >200 cycles.
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Adhesion of Li plating to electrode substrate and chemical stability of plated Li against electrolyte components are two essential factors affecting the cycling performance of Li metal in a ...rechargeable Li battery. Poor adhesion results in high contact resistance and further the formation of dead Li. Aiming to improve the adhesion of Li plating to Cu substrate, we plate a very thin tin layer as the primer for Li plating on the Cu substrate. By this way, Li metal is first reacted with tin to form a Li-Sn alloy, and then Li is cycled on resultant Li-Sn alloy so that the Li-Sn alloy functions as an “electric glue” to electrically connect the Li plating and Cu substrate. Attributed to the strong affinity between Li and Li-Sn alloy, the pre-plated tin layer is shown not only to enhance the adhesion of the plated Li to electrode substrate but also to improve the morphology of Li plating. Using a 1.0 m (molality) LiPF6 1:4 (wt.) fluoroethylene carbonate/ethylmethyl carbonate electrolyte, in this paper the effect of the tin primer layer on the Li cycling performance in a Li/Cu cell and a Cu/LiNi0.85Co0.10Al0.05O2 cell is demonstrated and discussed.
A pre-plated tin primer layer significantly enhances Li adhesion to electrode substrate and consequently improves the Li cycling performance. Display omitted
•A Sn-plated Cu foil is prepared as the electrode substrate for efficient Li electrodeposition.•Li cycling performance is improved from the view of Li adhesion to electrode substrate.•Tin primer layer significantly enhances the adhesion of Li deposit to electrode substrate.•The effect of tin primer layer on Li electrodeposition is evaluated in a “Li-free” cell.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Grid-scale energy storage is essential for reliable electricity transmission and renewable energy integration. Redox flow batteries (RFB) provide affordable and scalable solutions for stationary ...energy storage. However, most of the current RFB chemistries are based on expensive transition metal ions or synthetic organics. Here, we report a reversible chlorine redox flow battery starting from the electrolysis of aqueous NaCl electrolyte and the as-produced Cl
is extracted and stored in the carbon tetrachloride (CCl
) or mineral spirit flow. The immiscibility between the CCl
or mineral spirit and NaCl electrolyte enables a membrane-free design with an energy efficiency of >91% at 10 mA/cm
and an energy density of 125.7 Wh/L. The chlorine flow battery can meet the stringent price and reliability target for stationary energy storage with the inherently low-cost active materials (~$5/kWh) and the highly reversible Cl
/Cl
redox reaction.
All-solid-state lithium–sulfur batteries (ASSLSBs) using highly conductive sulfide-based solid electrolytes suffer from low sulfur utilization, poor cycle life, and low rate performance due to the ...huge volume change of the electrode and the poor electronic and ionic conductivities of S and Li2S. The most promising approach to mitigate these challenges lies in the fabrication of a sulfur nanocomposite electrode consisting of a homogeneous distribution of nanosized active material, solid electrolyte, and carbon. Here, we reported a novel bottom-up method to synthesize such a nanocomposite by dissolving Li2S as the active material, polyvinylpyrrolidone (PVP) as the carbon precursor, and Li6PS5Cl as the solid electrolyte in ethanol, followed by a coprecipitation and high-temperature carbonization process. Li2S active material and Li6PS5Cl solid electrolyte with a particle size of ∼4 nm were uniformly confined in a nanoscale carbon matrix. The homogeneous nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic and electronic conductivities enabled a mechanical robust and mixed conductive (ionic and electronic conductive) sulfur electrode for ASSLSB. A large reversible capacity of 830 mAh/g (71% utilization of Li2S) at 50 mA/g for 60 cycles with a high rate performance was achieved at room temperature even at a high loading of Li2S (∼3.6 mg/cm2). This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance all-solid-state lithium sulfur batteries.
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