硅基负极因具有高的理论比容量而成为极具发展潜力的下一代锂离子电池负极材料，但是其在充放电期间存在巨大的体积波动，导致固态电解质界面（SEI）反复破裂再生，界面膜不断增厚、阻抗持续增大，甚至出现电极破碎/粉化，严重缩短了电池的使用寿命，制约了该负极的实用化进程。为此，本文拟通过添加剂工程和溶剂化结构调控，缓解硅因体积变化对界面稳定性的负面影响，并详细研究了所配制的各款电解液基本理化性质、电极/电解液界面化学和电池电化学性能的影响规律，获得的主要研究结论如下：

电解液中适量添加三（三甲基硅基）硼酸酯（TMSB）可以明显提高硅基锂离子电池的循环稳定性和库伦效率，这是由于TMSB能够优先于溶剂进行牺牲性还原，形成的B-O基产物有效稳定了负极界面，促进了LiF沉积，抑制了电解液不可逆分解。当TMSB的质量分数为3%时，Si-C负极在100次循环后容量保持率达到81.5%，Si负极在60次循环后仍然保留2128.8 mAh g^-1的放电比容量。

采用氟化溶剂三氟乙基甲基碳酸酯（FEMC），以及低粘度、低介电常数、高氟碳比的1-（2,2,2-三氟乙氧基）-1,1,2,2-四氟乙烷（TFETFE）作为稀释剂，设计了全氟配方的局部高浓度电解液（LHCE-F）。通过分子动力学计算了LHCE-F的溶剂化模型，结果显示，TFETFE的加入促进了Li⁺与FIS^-阴离子的配位，LHCE-F很好的保留了高浓度电解液（HCE）的溶剂结构。电解液富阴离子的溶剂化簇有助于在正负极界面形成均匀稳定的界面膜。电化学性能测试结果显示，Si-C负极在0.5C恒流充放电150次后容量保持率可达78.6%，NCM811正极4.3V截止电压恒流充放电循环200次后的容量保持率达到84.3%。

采用LiFSI和LiDFOB构筑双盐局部高浓电解液（LHCE-S）。LiDFOB的加入有效改善了溶剂化结构，在正负极界面衍生了富无机界面相，有效提升了电池的循环稳定性。Raman表征和分子动力学（MD）研究表明，DFOB^-阴离子可以进入第一溶剂化层，减少了电解液中的游离溶剂，提升了电解液电化学窗口。利用XPS、SEM和TEM对Si-C负极进行界面表征，结果显示，有LiDFOB参与形成的界面膜均匀致密，且富无机锂组分，有效抑制了电解液的分解和界面副反应。使得Si-C/Li电池在循环200次后容量保持率仍然可达87%，平均库伦效率99.6%，NCM811/Li电池循环200次后容量保持率可达88.6%。

Silicon-based anodes, with their exceptionally high theoretical specific capacity, have emerged as a highly promising next-generation negative electrode material for lithium-ion batteries. However, their severe volume fluctuations during charge/discharge cycles lead to repeated cracking and reformation of the solid electrolyte interphase (SEI), resulting in continuous thickening of the interfacial layer, increasing impedance, and even electrode fragmentation/pulverization. These issues significantly shorten battery cycle life and hinder practical commercialization.To address these challenges, this study employs additive engineering and solvation structure modulation to mitigate the negative impact of silicon’s volume changes on interfacial stability. A systematic investigation was conducted on the fundamental physicochemical properties of the formulated electrolytes, electrode/electrolyte interfacial chemistry, and their influence on battery electrochemical performance. The key findings are summarized as follows:

1)The addition of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive significantly enhances the cycling stability and Coulombic efficiency of silicon-based lithium-ion batteries. TMSB undergoes preferential sacrificial reduction over solvents, generating B-O-rich interfacial products that stabilize the anode interface, promote LiF deposition, and suppress irreversible electrolyte decomposition. At an optimal 3 wt% TMSB concentration, the Si-C composite anode achieves 81.5% capacity retention after 100 cycles, while a pure Si anode maintains a reversible discharge capacity of 2128.8 mAh g⁻¹ after 60 cycles.

2)A locally high-concentration fluorinated electrolyte (LHCE-F) was formulated using fluorinated solvents—methyl 2,2,2-trifluoroethyl carbonate (FEMC) as the primary solvent and 1-(2,2,2-trifluoroethoxy)-1,1,2,2-tetrafluoroethane (TFETFE) as a diluent, selected for its low viscosity, low dielectric constant, and high fluorine-to-carbon ratio. Molecular dynamics simulations of LHCE-F’s solvation structure revealed that TFETFE enhances Li⁺ coordination with FSI⁻ anions while preserving the intrinsic solvation network of the high-concentration electrolyte (HCE). This anion-rich solvation cluster facilitates the formation of uniform and stable interfacial films on both electrodes. Electrochemical testing demonstrated exceptional performance: the Si-C anode retained 78.6% capacity after 150 cycles at 0.5C, while the NCM811 cathode achieved 84.3% capacity retention after 200 cycles at a 4.3V cutoff voltage.

3)A dual-salt locally high-concentration electrolyte (LHCE-S) was designed using LiFSI and LiDFOB. The incorporation of LiDFOB effectively modulates the solvation structure, generating inorganic-rich interphases on both electrodes to enhance cycling stability. Raman spectroscopy and molecular dynamics (MD) studies reveal that DFOB⁻ anions participate in the primary solvation sheath, reducing free solvent molecules and expanding the electrolyte's electrochemical stability window. XPS, SEM, and TEM characterization of the Si-C anode interface confirm that LiDFOB promotes the formation of a uniform, dense, and inorganic-dominated (e.g,LiF,LiₓBO_y) interphase, effectively suppressing electrolyte decomposition and parasitic reactions. Consequently, the Si-C/Li cell achieves 87% capacity retention after 200 cycles with an average Coulombic efficiency of 99.6%, while the NCM811/Li cell maintains 88.6% capacity retention under the same cycling conditions.

[1]Banek N A, McKenzie Jr K R, Abele D T, et al. Sustainable conversion of biomass to rationally designed lithium-ion battery graphite[J]. Scientific Reports, 2022, 12(1): 8080.

[2]Zhao L, Ding B, Qin X Y, et al. Revisiting the roles of natural graphite in ongoing lithium‐ion batteries[J]. Advanced Materials, 2022, 34(18): 2106704.

[3]Sun L, Liu Y, Shao R, et al. Recent progress and future perspective on practical silicon anode-based lithium ion batteries[J]. Energy Storage Materials, 2022, 46: 482-502.

[4]Chae S, Choi S H, Kim N, et al. Integration of graphite and silicon anodes for the commercialization of high‐energy lithium‐ion batteries[J]. Angewandte Chemie International Edition, 2020, 59(1): 110-135.

[5]Julien C M, Mauger A. Fabrication of Li4Ti5O12 (LTO) as anode material for Li-Ion batteries[J]. Micromachines, 2024, 15(3): 310.

[6]Nzereogu P U, Omah A D, Ezema F I, et al. Anode materials for lithium-ion batteries: A review[J]. Applied Surface Science Advances, 2022, 9: 100233.

[7]Shen X, Liu H, Cheng X B, et al. Beyond lithium ion batteries: Higher energy density battery systems based on lithium metal anodes[J]. Energy Storage Materials, 2018, 12: 161-175.

[8]Hossain M H, Chowdhury M A, Hossain N, et al. Advances of lithium-ion batteries anode materials—A review[J]. Chemical Engineering Journal Advances, 2023, 16: 100569.

[9]Zhang X, Yang Y, Zhou Z. Towards practical lithium-metal anodes[J]. Chemical Society Reviews, 2020, 49(10): 3040-3071.

[10]Lin D, Liu Y, Cui Y. Reviving the lithium metal anode for high-energy batteries[J]. Nature Nanotechnology, 2017, 12(3): 194-206.

[11]Xu R, Ding J F, Ma X X, et al. Designing and demystifying the lithium metal interface toward highly reversible batteries[J]. Advanced Materials, 2021, 33(52): 2105962.

[12]Wei W Q, Liu B Q, Gan Y Q, et al. Protecting lithium metal anode in all-solid-state batteries with a composite electrolyte[J]. Rare Metals, 2021, 40: 409-416.

[13]Qi Y, Wang G, Li S, et al. Recent progress of structural designs of silicon for performance-enhanced lithium-ion batteries[J]. Chemical Engineering Journal, 2020, 397: 125380.

[14]Jin Y, Zhu B, Lu Z, et al. Challenges and recent progress in the development of Si anodes for lithium‐ion battery[J]. Advanced Energy Materials, 2017, 7(23): 1700715.

[15]Liu Y K, Zhao C Z, Du J, et al. Research progresses of liquid electrolytes in lithium‐ion batteries[J]. Small, 2023, 19(8): 2205315.

[16]Yong T, Zhang L, Wang J, et al. Novel choline-based ionic liquids as safe electrolytes for high-voltage lithium-ion batteries[J]. Journal of Power Sources, 2016, 328: 397-404.

[17]Ehteshami N, Ibing L, Stolz L, et al. Ethylene carbonate-free electrolytes for Li-ion battery: Study of the solid electrolyte interphases formed on graphite anodes[J]. Journal of Power Sources, 2020, 451: 227804.

[18]Zhang X, Cui Z, Jo E, et al. Inhibition of transition-metal dissolution with advanced electrolytes in batteries with silicon-graphite anodes and high-nickel cathodes[J]. Energy Storage Materials, 2023, 56: 562-571.

[19]Chen L, Fan X, Hu E, et al. Achieving high energy density through increasing the output voltage: A highly reversible 5.3 V battery[J]. Chem, 2019, 5(4): 896-912.

[20]Ouyang D, Wang K, Pang Y, et al. Optimal blend between carbonate solvents and fluoroethylene carbonate for high-voltage and high-safety Li (Ni0.8Mn0.1Co0.1) O2 lithium-ion cells[J]. ACS Applied Energy Materials, 2023, 6(3): 2063-2071.

[21]Kim K, Ma H, Park S, et al. Electrolyte-additive-driven interfacial engineering for high-capacity electrodes in lithium-ion batteries: promise and challenges[J]. ACS Energy Letters, 2020, 5(5): 1537-1553.

[22]Yamazaki S, Tatara R, Mizuta H, et al. Consumption of fluoroethylene carbonate electrolyte-additive at the Si–graphite negative electrode in Li and Li-ion cells[J]. The Journal of Physical Chemistry C, 2023, 127(29): 14030-14040.

[23]Qiao Y, Yang H, Chang Z, et al. A high-energy-density and long-life initial-anode-free lithium battery enabled by a Li2O sacrificial agent[J]. Nature Energy, 2021, 6(6): 653-662.

[24]Lu H, Lei Y, Ma Y, et al. 4-fluorophenylboronic anhydride as an impurity-scavenging agent and two-sided interface modifier for high-performance lithium ion batteries[J]. Chemical Engineering Journal, 2024, 491: 152180.

[25]Liu H, Li T, Xu X, et al. Stable interfaces constructed by concentrated ether electrolytes to render robust lithium metal batteries[J]. Chinese Journal of Chemical Engineering, 2021, 37: 152-158.

[26]Liu J, Yuan B, Dong L, et al. Constructing low‐solvation electrolytes for next‐generation lithium‐ion batteries[J]. Batteries & Supercaps, 2022, 5(10): e202200256.

[27]Sun L, Liu Y, Wang L, et al. Advances and future prospects of micro‐silicon anodes for high‐energy‐density lithium‐ion batteries: a comprehensive review[J]. Advanced Functional Materials, 2024, 34(39): 2403032.

[28]Wang S, Shi J, Liu Z, et al. Advanced ether‐based electrolytes for lithium‐ion batteries[J]. Advanced Energy Materials, 2024, 14(37): 2401526.

[29]Hu J, Ji Y, Zheng G, et al. Influence of electrolyte structural evolution on battery applications: Cationic aggregation from dilute to high concentration[J]. Aggregate, 2022, 3(1): e153.

[30]Li X, Chen Z, Liu X, et al. Efficient lithium transport and reversible lithium plating in silicon anodes: Synergistic design of porous structure and LiF‐rich SEI for fast charging[J]. Advanced Functional Materials, 2024, 34(33): 2401686.

[31]Liu G, Xia M, Gao J, et al. Dual-salt localized high-concentration electrolyte for long cycle life silicon-based lithium-ion batteries[J]. ACS Applied Materials & Interfaces, 2023, 15(2): 3586-3598.

[32]秦雪英, 汪靖伦, 张灵志. 锂离子电池有机硅电解液[J]. 化学进展,2012,24(05): 810-822.

[33]Lee J, Jeong J Y, Ha J, et al. Understanding solid electrolyte interface formation on graphite and silicon anodes in lithium-ion batteries: Exploring the role of fluoroethylene carbonate[J]. Electrochemistry Communications, 2024, 163: 107708.

[34]Kim H, Kim T H, Park S S, et al. Interphasial engineering via individual moiety functionalized organosilane single-molecule for extreme quick rechargeable SiO/NCM811 lithium-ion batteries[J]. ACS Applied Materials & Interfaces, 2021, 13(37): 44348-44357.

[35]Cheng W, Li N, Liu J, et al. Solid electrolyte interface film-forming and surface-stabilizing bifunctional 1,2-bis((trimethylsilyl)oxy) benzene as novel electrolyte additive for silicon-based lithium-ion batteries[J]. ACS Applied Materials & Interfaces, 2023, 15(44): 51025-51035.

[36]Luo S, Ge C, Ou L, et al. Construction of stable two-sided interface via the addition of phenylboric acid in Lithium-ion batteries[J]. Electrochimica Acta, 2024, 498: 144684.

[37]Wang J, Dong H, Wang P, et al. Adjusting the solvation structure with tris (trimethylsilyl) borate additive to improve the performance of LNCM half cells[J]. Journal of Energy Chemistry, 2022, 67: 55-64.

[38]Yu H, Yang Z, Han Q, et al. Operando building of a superior interface hybrid film enables chemomechanically durable Co-free Ni-rich cathodes[J]. ACS Nano, 2024.

[39]von Kolzenberg L, Latz A, Horstmann B. Chemo‐mechanical model of SEI growth on silicon electrode particles[J]. Batteries & Supercaps, 2022, 5(2): e202100216.

[40]Wen Z, Wu F, Li L, et al. Electrolyte design enabling stable solid electrolyte interface for high-performance silicon/carbon anodes[J]. ACS Applied Materials & Interfaces, 2022, 14(34): 38807-38814.

[41]Medina-Santos J I, Palma J, Ventosa E, et al. Insulating characteristics and ionic conductivity properties of the solid electrolyte interface in lithium-ion batteries to improve a redox-mediated enhanced coulometry Method[J]. Journal of The Electrochemical Society, 2023, 170(9): 090520.

[42]David H K, Chen P T, Yan W M, et al. Perspective of material evolution Induced by sinusoidal reflex charging in lithium-ion batteries[J]. Heliyon, 2024, 10(10).

[43]Xu Z, Huang R, Huang P, et al. Weakly solvated electrolyte enables the robust solid electrolyte interface on SiOx anodes for lithium-ion battery[J]. Chemical Engineering Journal, 2024: 157028.

[44]Huang L B, Li G, Lu Z Y, et al. Trans-difluoroethylene carbonate as an electrolyte additive for microsized SiOx@C anodes[J]. ACS Applied Materials & Interfaces, 2021, 13(21): 24916-24924.

[45]Lee J, Jeong J Y, Ha J, et al. Understanding solid electrolyte interface formation on graphite and silicon anodes in lithium-ion batteries: Exploring the role of fluoroethylene carbonate[J]. Electrochemistry Communications, 2024, 163: 107708.

[46]Xiao Y, Shi X, Zheng T, et al. Dual role of bis (borate) additive in electrode/electrolyte interface layer construction for high-voltage NCM523 cathode[J]. ACS Applied Energy Materials, 2023, 6(9): 4817-4824.

[47]Lu K, Lu S, Gu T, et al. Onium salts-derived B and P dual-doped carbon microspheres as anode material for high-performance sodium-ion batteries[J]. Electrochemistry Communications, 2019, 103: 22-26.

[48]Wang A, Kadam S, Li H, et al. Review on modeling of the anode solid electrolyte interphase (SEI) for lithium-ion batteries[J]. NPJ Computational Materials, 2018, 4(1): 15.

[49]Huangzhang E, Zeng X, Yang T, et al. A localized high-concentration electrolyte with lithium bis (fluorosulfonyl) imide (LiFSI) salt and F-containing cosolvents to enhance the performance of Li||LiNi0.8Co0.1Mn0.1O2 lithium metal batteries[J]. Chemical Engineering Journal, 2022, 439: 135534.

[50]Kong L, Li C, Jiang J, et al. Li-ion battery fire hazards and safety strategies[J]. Energies, 2018, 11(9): 2191.

[51]Qin M, Zeng Z, Cheng S, et al. Challenges and strategies of formulating low‐temperature electrolytes in lithium‐ion batteries[J]. Interdisciplinary Materials, 2023, 2(2): 308-336.

[52]Tan J, Matz J, Dong P, et al. A growing appreciation for the role of LiF in the solid electrolyte interphase[J]. Advanced Energy Materials, 2021, 11(16): 2100046.

[53]Ding K, Xu C, Peng Z, et al. Tuning the solvent alkyl chain to tailor electrolyte solvation for stable Li-metal batteries[J]. ACS Applied Materials & Interfaces, 2022, 14(39): 44470-44478.

[54]Shi J, Xu C, Lai J, et al. An amphiphilic molecule‐regulated core‐shell‐solvation electrolyte for Li‐metal batteries at ultra‐low temperature[J]. Angewandte Chemie, 2023, 135(13): e202218151.

[55]Zhao C, Amine K, Xu G L. Nontraditional approaches to enable high-energy and long-life lithium–sulfur batteries[J]. Accounts of Chemical Research, 2023, 56(19): 2700-2712.

[56]Chen X, Yu H. A computational review on localized high‐concentration electrolytes in lithium batteries[J]. ChemElectroChem, 2024, 11(23): e202400444.

[57]Sun L, Liu Y, Wang L, et al. Advances and future prospects of micro‐silicon anodes for high‐energy‐density lithium‐ion batteries: a comprehensive review[J]. Advanced Functional Materials, 2024, 34(39): 2403032.

[58]An S J, Li J, Daniel C, et al. The state of understanding of the lithium-ion-battery graphite solid electrolyte interphase (SEI) and its relationship to formation cycling[J]. Carbon, 2016, 105: 52-76.

[59]Feng K, Li M, Liu W, et al. Silicon‐based anodes for lithium‐ion batteries: from fundamentals to practical applications[J]. Small, 2018, 14(8): 1702737.

[60]Cai Y, Zhang H, Cao Y, et al. Synthesis, application and industrialization of LiFSI: A review and perspective[J]. Journal of Power Sources, 2022, 535: 231481.

[61]Wu H, Feng W, Armand M, et al. Lithium bis (fluorosulfonyl) imide for stabilized interphases on conjugated dicarboxylate electrode[J]. ACS Applied Materials & Interfaces, 2023, 16(37): 48748-48756.

[62]Wu Q, Mao S, Wang Z, et al. Improving LiNixCoyMn1−x−yO2 cathode electrolyte interface under high voltage in lithium ion batteries[J]. Nano Select, 2020, 1(1): 111-134.

[63]Dong T, Zhang S, Ren Z, et al. Electrolyte engineering toward high performance high nickel (Ni≥ 80%) lithium‐ion batteries[J]. Advanced Science, 2024, 11(7): 2305753.

[64]Quilty C D, Bernardez E J M, Nicoll A, et al. Lithium-ion battery functionality over broad operating conditions via local high concentration fluorinated ester electrolytes[J]. RSC Applied Interfaces, 2024, 1(5): 1077-1092.

[65]Zhu X F, Li X, Liang T Q, et al. Electrolyte perspective on stabilizing LiNi0. 8Co0. 1Mn0. 1O2 cathode for lithium-ion batteries[J]. Rare Metals, 2023, 42(2): 387-398.

[66]Zu C, Yu H, Li H. Enabling the thermal stability of solid electrolyte interphase in Li‐ion battery[J]. InfoMat, 2021, 3(6): 648-661.

[67]Xia M, Lin M, Liu G, et al. Stable cycling and fast charging of high-voltage lithium metal batteries enabled by functional solvation chemistry[J]. Chemical Engineering Journal, 2022, 442: 136351.

[68]Li J, Fan Z, Guo J, et al. Insights into the efficient roles of boron-containing additives for Li-ion batteries[J]. Surfaces and Interfaces, 2024: 104309.

[69]Luo D, Li M, Zheng Y, et al. Electrolyte design for lithium metal anode‐based batteries toward extreme temperature application[J]. Advanced Science, 2021, 8(18): 2101051.

[70]Jin Y, Zhu B, Lu Z, et al. Challenges and recent progress in the development of Si anodes for lithium‐ion battery[J]. Advanced Energy Materials, 2017, 7(23): 1700715.

[71]Xu G, Shangguan X, Dong S, et al. Formulation of blended‐lithium‐salt electrolytes for lithium batteries[J]. Angewandte Chemie International Edition, 2020, 59(9): 3400-3415.

[72]Fan X, Wang C. High-voltage liquid electrolytes for Li batteries: progress and perspectives[J]. Chemical Society Reviews, 2021, 50(18): 10486-10566.

[73]Li J, Fan Z, Guo J, et al. Insights into the efficient roles of boron-containing additives for Li-ion batteries[J]. Surfaces and Interfaces, 2024: 104309.

[74]Wang S, Shi J, Liu Z, et al. Advanced ether‐based electrolytes for lithium‐ion batteries[J]. Advanced Energy Materials, 2024, 14(37): 2401526.