2,2,2-Trifluoroethyl trifluoroacetate as effective electrolyte additive for uniform Li deposition in lithium metal batteries

Yang, Shitu; Hao, Mingtian; Wang, Zhe; Xie, Zhengkun; Cai, Zengjian; Hu, Mingzhen; Chen, Bo‐Zhen; Wang, Lei; Zhou, Kebin

doi:10.1016/j.cej.2022.134897

Cited by 22 publications

(12 citation statements)

References 55 publications

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“…As shown in Figure 3e,f, for the symmetric battery with 0.01% AED, the initial impedance value is 5096 Ω, and then the value drops to 738 Ω after 50 cycles. The decrease in impedance corresponds to the activation process of the symmetrical battery at the early stage, [21] in which a stable SEI is gradually formed. After 100 or even 150 cycles, the resistance value shows a slight increase, which can be attributed to the inevitable increase in the thickness of the SEI during the cycle.…”

Section: Resultsmentioning

confidence: 99%

Optimized Solid Electrolyte Interphase and Solvation Structure of Potassium Ions in Carbonate Electrolytes for High‐Performance Potassium Metal Batteries

Jiang

et al. 2023

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The introduction of electrolyte additives is one of the most potential strategies to improve the performance of potassium metal batteries (PMBs). However, designing an additive that can alter the K+ solvation shell and essentially inhibit K dendrite remains a challenge. Herein, the amyl‐triphenyl‐phosphonium bromide was introduced as an additive to build a stable solid electrolyte interphase layer. The amyl‐TPP cations can form a cation shielding layer on the metal surface during the nucleation stage, preventing K+ from gathering at the tip to form K dendrites. Besides, the cations can be preferentially reduced to form KxPy with fast K+ transport kinetics. The Br− anions, as Lewis bases with strong electronegativity, can not only coordinate the Lewis acid pentafluoride to inhibit the formation of HF, but also change the K+ solvation structure to reduce solvent molecules in the first solvation structure. Therefore, the symmetrical battery exhibits a low deposition overpotential of 123 mV at 0.1 mA cm−2 over 4200 h cycle life. The full battery, paried with a perylene‐tetracarboxylic dianhydride (PTCDA) cathode, possesses a cycle life of 250 cycles at 2 C and 81.9% capacity retention. This work offers a reasonable electrolyte design to obtain PMBs with long‐term stablity and safety.

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Section: Resultsmentioning

confidence: 99%

Optimized Solid Electrolyte Interphase and Solvation Structure of Potassium Ions in Carbonate Electrolytes for High‐Performance Potassium Metal Batteries

Jiang

et al. 2023

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“…To address these problems, researchers have proposed many effective strategies, such as an artificial SEI layer, electrolyte composition, and anode engineering. , (I) Construction of an artificial SEI layer. During the electrochemical process, the composition of the naturally formed SEI layer is unstable, and the physical and chemical anisotropy easily leads to an increase in the inhomogeneity of lithium flux and lithium deposition, which accelerates the formation of lithium dendrites. − Therefore, it is proposed to build artificial SEI layers to increase the transport capacity of lithium ions, smooth the lithium deposition process, and increase the mechanical strength to limit lithium dendrite growth. Recently reported artificial SEI film materials include lithium carboxymethylcellulose lithium (CMC-Li), dihydroxy violet (DHV), graphitic carbon nitride (g-C 3 N 4 )/MXene, etc.…”

Section: Introductionmentioning

confidence: 99%

Lithiophilic Interface Layer Induced Uniform Deposition for Dendrite-free Lithium Metal Anodes in a 3D Polyethersulfone Frame

Cao

Huang

et al. 2023

ACS Appl. Mater. Interfaces

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Lithium metal anodes possess ultrahigh theoretical specific capacity for next-generation lithium metal batteries, but the infinite volume expansion and the growth of lithium dendrites remain a huge obstacle to their commercialization. Therefore, here, we construct a CuO-loaded 3D polyethersulfone (PES) nanofiber frame onto a lithiophilic Cu 2 O/Cu substrate to promote the lithium storage performance of the composite anode, and the 3D frame can effectively alleviate the volume expansion of lithium (Li) metal anodes. Meanwhile, lithium reacts with CuO in the composite nanofiber and Cu 2 O of the substrate to generate Li 2 O, which can strengthen the solid electrolyte interface (SEI) layer and achieve the uniform deposition of lithium. In addition, the combination of the heat treatment method and electrospinning technology solves the problem of poor adhesion between the fiber film and the substrate. As a result, the PES/CuO−Cu 2 O (PCC) composite current collector still maintains a smooth and flat lithium-depositing layer at 5 mA cm −2 . The PCC-assembled Li||Cu halfcell can operate stably for 320 cycles at 0.5 mA cm −2 , which is about 4 times that of bare Cu. Furthermore, symmetrical batteries with PCC@Li can maintain excellent cycle stability for 1770 h. Accordingly, this work provides a low-cost and highly effective strategy for stabilizing the lithium metal anode.

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“…Lithium metal is considered as one of the most ideal anode materials because of its high specific capacity (3860 mAh g −1 ), low electrochemical potential (3.04 V), and low density (0.534 g cm −3 ). [1][2][3][4][5][6][7] However, the distribution of Li-ion flux at mobility of Li + . [38] Furthermore, carbonized polymer dots (CPDs) with special cross-linking structures and high stability to pH and ionic strength are expected to improve the stability of electrolytes.…”

Section: Introductionmentioning

confidence: 99%

“…[11,[20][21][22][23][24] Nowadays, diverse small-molecule electrolyte additives, such as hexadecyl trimethylammonium chloride, p-hydroxybenzoic acid, hexafluoroacetylacetone, and 2,2,2-trifluoroethyl trifluoroacetate, have been used to direct Li deposition by forming a more protective solid electrolyte interphase (SEI) layer. [1,2,25] Although considerable achievements have been obtained, the dissociated anions from small molecule electrolyte additives usually pair with Li + , and the random motion of the ion pair seriously damages the effective diffusion/transfer of Li + in the electrolyte, resulting in undesirable ion transfer number and electrochemical performance. [26] Moreover, non-negligible drawbacks of high cost and difficulty in synthesis also hinder their practical application.…”

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confidence: 99%

Carbonized Polymer Dots with Controllable N, O Functional Groups as Electrolyte Additives to Achieve Stable Li Metal Batteries

Wang

Song

Yang

et al. 2023

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Electrolyte additive is an effective strategy to inhibit the uncontrolled growth of Li dendrites for lithium metal batteries (LMBs). However, most of the additives are complex synthesis and prone to decompose in cycling. Herein, in order to guide the homogeneous deposition of Li+, carbonized polymer dots (CPDs) as electrolyte additives are successfully designed and synthesized by microwave (M‐CPDs) and hydrothermal (H‐CPDs) approaches. The controllable functional groups containing N or O (especially pyridinic‐N, pyrrolic‐N, and carboxyl group) enable CPDs to keep stable in electrolytes for at least 3 months. Meanwhile, the clusters formed between CPDs and Li+ through electrostatic interaction effectively guide the uniform Li dispersion and limit the “tip effect” and dendrite formation. Moreover, as lithiophilic groups increase, the strong electrostatic interference for the solvation effect of Li+ in the electrolyte is formed, which induces faster Li+ diffusion/transfer. As expected, H‐CPDs achieve the ultra‐even Li+ transfer. The corresponding Li//LiFePO4 full cell delivers a high capacity retention rate of 93.8% after 200 cycles, which is much higher than that of the cells without additives (61.2%) and with M‐CPDs (83.7%) as additives. The strategy in this work provides a theoretical direction for CPDs as electrolyte additives used in energy storage devices.

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2,2,2-Trifluoroethyl trifluoroacetate as effective electrolyte additive for uniform Li deposition in lithium metal batteries

Cited by 22 publications

References 55 publications

Optimized Solid Electrolyte Interphase and Solvation Structure of Potassium Ions in Carbonate Electrolytes for High‐Performance Potassium Metal Batteries

Optimized Solid Electrolyte Interphase and Solvation Structure of Potassium Ions in Carbonate Electrolytes for High‐Performance Potassium Metal Batteries

Lithiophilic Interface Layer Induced Uniform Deposition for Dendrite-free Lithium Metal Anodes in a 3D Polyethersulfone Frame

Carbonized Polymer Dots with Controllable N, O Functional Groups as Electrolyte Additives to Achieve Stable Li Metal Batteries

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