Practical development and challenges of garnet-structured Li₇La₃Zr₂O₁₂ electrolytes for all-solid-state lithium-ion batteries: A review

Abstract

All-solid-state Li-ion batteries (ASSLIBs) have been widely studied to achieve Li-ion batteries (LIBs) with high safety and energy density. Recent reviews and experimental papers have focused on methods that improve the ionic conductivity, stabilize the electrochemical performance, and enhance the electrolyte/electrode interfacial compatibility of several solid-state electrolytes (SSEs), including oxides, sulfides, composite and gel electrolytes, and so on. Garnet-structured Li₇La₃Zr₂O₁₂ (LLZO) is highly regarded an SSE with excellent application potential. However, this type of electrolyte also possesses a number of disadvantages, such as low ionic conductivity, unstable cubic phase, and poor interfacial compatibility with anodes/cathodes. The benefits of LLZO have urged many researchers to explore effective solutions to overcome its inherent limitations. Herein, we review recent developments on garnet-structured LLZO and provide comprehensive insights to guide the development of garnet-structured LLZO-type electrolytes. We not only systematically and comprehensively discuss the preparation, element doping, structure, stability, and interfacial improvement of LLZOs but also provide future perspectives for these materials. This review expands the current understanding on advanced solid garnet electrolytes and provides meaningful guidance for the commercialization of ASSLIBs.

Keywords

all solid-state lithium-ion batteries / garnet-structured LLZO electrolytes / interfacial compatibility / polymer-ceramic composite electrolytes

References

[1] Yang T, Liu HJ, Bai F, Wang EH, Chen JH, Chou KC, Hou XM. Supercapacitor electrode based on few-layer h-BNNSs/rGO composite for wide-temperature-range operation with robust stable cycling performance. Int. J. Miner. Metall. Mater., 2020, 27(2): 220.

[2] L.T. Zhang, Z. Sun, Z.L. Cai, N.H. Yan, X. Lu, X.Q. Zhu, and L.X. Chen, Enhanced hydrogen storage properties of MgH₂ by the synergetic catalysis of Zr_0.4Ti_0.6Co nanosheets and carbon nanotubes, Appl. Surf. Sci., 504(2020), art. No. 144465.

[3] Y.P. Li, Q.B. Zhang, Y.F. Yuan, H.D. Liu, C.H. Yang, Z. Lin, and J. Lu, Surface amorphization of vanadium dioxide (B) for K-ion battery, Adv. Energy Mater., 10(2020), No. 23, art. No. 2000717.

[4] Díaz-González F, Sumper A, Gomis-Bellmunt O, Villafáfila-Robles R. A review of energy storage technologies for wind power applications. Renewable Sustainable Energy Rev., 2012, 16(4): 2154.

[5] Chen QH, Cheng Y, Liu HD, Zhang QB, Petrova V, Chen HX, Liu P, Peng DL, Liu ML, Wang MS. Hierarchical design of Mn₂P nanoparticles embedded in N, P-codoped porous carbon nanosheets enables highly durable lithium storage. ACS Appl. Mater. Interfaces, 2020, 12(32): 36247.

[6] Zhang LT, Ji L, Yao ZD, Yan NH, Sun Z, Yang XL, Zhu XQ, Hu SL, Chen LX. Facile synthesized Fe nanosheets as superior active catalyst for hydrogen storage in MgH₂. Int. J. Hydrogen Energy, 2019, 44(39): 21955.

[7] Zhang LT, Cai ZL, Yao ZD, Ji L, Sun Z, Yan NH, Zhang BY, Xiao BB, Du J, Zhu XQ, Chen LX. A striking catalytic effect of facile synthesized ZrMn₂ nanoparticles on the de/rehydrogenation properties of MgH₂. J. Mater. Chem. A, 2019, 7(10): 5626.

[8] J.M. Chen, Y. Cheng, Q.B. Zhang, C. Luo, H.Y. Li, Y. Wu, H.H. Zhang, X. Wang, H.D. Liu, X. He, J.J. Han, D.L. Peng, M.L. Liu, and M.S. Wang, Designing and understanding the superior potassium storage performance of nitrogen/phosphorus co-doped hollow porous bowl-like carbon anodes, Adv. Funct. Mater., 31(2021), No. 1, art. No. 2007158.

[9] Zhao LZ, Wu HH, Yang CH, Zhang QB, Zhong GM, Zheng ZM, Chen HX, Wang JM, He K, Wang BL, Zhu T, Zeng XC, Liu ML, Wang MS. Mechanistic origin of the high performance of yolk@shell Bi₂S₃@N-doped carbon nanowire electrodes. ACS Nano, 2018, 12(12): 12597.

[10] Han Y, Liu SY, Cui L, Xu L, Xie J, Xia XK, Hao WK, Wang B, Li H, Gao J. Graphene-immobilized flowerlike Ni₃S₂ nanoflakes as a stable binder-free anode material for sodium-ion batteries. Int. J. Miner. Metall. Mater., 2018, 25(1): 88.

[11] L. Chen, W.X. Li, L.Z. Fan, C.W. Nan, and Q. Zhang, Intercalated electrolyte with high transference number for dendrite-free solid-state lithium batteries, Adv. Funct. Mater., 29(2019), No. 28, art. No. 1901047.

[12] Yang XL, Ye YS, Wang ZM, Zhang ZH, Zhao YL, Yang F, Zhu ZY, Wei T. POM-based MOF-derived Co₃O₄/CoMoO₄ nanohybrids as anodes for high-performance lithium-ion batteries. ACS Omega, 2020, 5(40): 26230.

[13] Yang XY, Wei T, Li JS, Sheng N, Zhu PP, Sha JQ, Wang T, Lan YQ. Polyoxometalate-incorporated metall-apillararene/metallacalixarene metal-organic frameworks as anode materials for lithium ion batteries. Inorg. Chem., 2017, 56(14): 8311.

[14] Zhang M, Wei T, Zhang AM, Li SL, Shen FC, Dong LZ, Li DS, Lan YQ. Polyoxomolybdate-polypyrrole/reduced graphene oxide nanocomposite as high-capacity electrodes for lithium storage. ACS Omega, 2017, 2(9): 5684.

[15] Cheng Y, Zhang LQ, Zhang QB, Li J, Tang YF, de Delmas C, Zhu T, Winter M, Wang MS, Huang JY. Understanding all solid-state lithium batteries through in situ transmission electron microscopy. Mater. Today, 2021, 42, 137.

[16] Zheng ZM, Wu HH, Liu HD, Zhang QB, He X, Yu SC, Petrova V, Feng J, Kostecki R, Liu P, Peng DL, Liu ML, Wang MS. Achieving fast and durable lithium storage through amorphous FeP nanoparticles encapsulated in ultrathin 3D P-doped porous carbon nanosheets. ACS Nano, 2020, 14(8): 9545.

[17] Zheng ZM, Li P, Huang JS, Liu HD, Zao Y, Hu ZL, Zhang L, Chen HX, Wang MS, Peng DL, Zhang QB. High performance columnar-like Fe₂O₃@carbon composite anode via yolk@shell structural design. J. Energy Chem., 2020, 41, 126.

[18] Yu QP, Han D, Lu QW, He YB, Li S, Liu Q, Han CP, Kang FY, Li BH. Constructing effective interfaces for Li_1.5Al_0.5Ge_1.5(PO₄)₃ pellets to achieve room-temperature hybrid solid-state lithium metal batteries. ACS Appl. Mater. Interfaces, 2019, 11(10): 9911.

[19] H. Xie, C.P. Yang, K. Fu, Y.G. Yao, F. Jiang, E. Hitz, B.Y. Liu, S. Wang, and L.B. Hu, Flexible, scalable, and highly conductive garnet-polymer solid electrolyte templated by bacterial cellulose, Adv. Energy Mater., 8(2018), No. 18, art. No. 1703474.

[20] Zhang H, Li CM, Piszcz M, Coya E, Rojo T, Rodriguez-Martinez LM, Armand M, Zhou ZB. Single lithium-ion conducting solid polymer electrolytes: Advances and perspectives. Chem. Soc. Rev., 2017, 46(3): 797.

[21] Zhao EQ, Guo YD, Xu GR, Yuan L, Liu JC, Li XB, Yang L, Ma JJ, Li YC, Fan SM. High ionic conductivity Y doped Li_1.3Al_0.3Ti_1.7(PO₄)₃ solid electrolyte. J. Alloys Compd., 2019, 782, 384.

[22] Zha WP, Chen F, Yang DJ, Shen Q, Zhang LM. High-performance Li_6.4La₃Zr_1.4Ta_0.6O₁₂/poly(ethylene oxide)/succinonitrile composite electrolyte for solid-state lithium batteries. J. Power Sources, 2018, 397, 87.

[23] L. Luo, J.Y. Li, H.Y. Asl, and A. Manthiram, A 3D lithiophilic Mo₂N-modified carbon nanofiber architecture for dendrite-free lithium-metal anodes in a full cell, Adv. Mater., 31(2019), No. 48, art. No. 1904537.

[24] Zhang MS, Liu RJ, Wang ZK, Xing XY, Liu YG, Deng BB, Yang T. Electrolyte additive maintains high performance for dendrite-free lithium metal anode. Chin. Chem. Lett., 2020, 31(5): 1217.

[25] L.H. Xu, G.B. Li, J.X. Guan, L.L. Wang, J.T. Chen, and J.R. Zheng, Garnet-doped composite polymer electrolyte with high ionic conductivity for dendrite-free lithium batteries, J. Energy Storage, 24(2019), art. No. 100767.

[26] Guo F, Wang YL, Kang T, Liu CH, Shen YB, Lu W, Wu XD, Chen LW. A Li-dual carbon composite as stable anode material for Li batteries. Energy Storage Mater., 2018, 15, 116.

[27] Tian SK, Shao BW, Wang ZQ, Li SD, Liu XY, Zhao YB, Li L. Organic ionic plastic crystal as electrolyte for lithium-oxygen batteries. Chin. Chem. Lett., 2019, 30(6): 1289.

[28] Zhou D, Tkacheva A, Tang X, Sun B, Shanmukaraj D, Li P, Zhang F, Armand M, Wang GX. Stable conversion chemistry-based lithium metal batteries enabled by hierarchical multifunctional polymer electrolytes with near-single ion conduction. Angew. Chem. Int. Ed., 2019, 58(18): 6001.

[29] Xia Y, Wang XL, Xia XH, Xu RC, Zhang SZ, Wu JB, Liang YF, Gu CD, Tu JP. A newly designed composite gel polymer electrolyte based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) for enhanced solid-state lithium-sulfur batteries. Chem. Eur. J., 2017, 23(60): 15203.

[30] He JY, Liu JQ, Li J, Lai YQ, Wu XF. Enhanced ionic conductivity and electrochemical capacity of lithium ion battery based on PVDF-HFP/HDPE membrane. Mater. Lett., 2016, 170, 126.

[31] Zhou WD, Wang SF, Li YT, Xin S, Manthiram A, Goodenough JB. Plating a dendrite-free lithium anode with a polymer/ceramic/polymer sandwich electrolyte. J. Am. Chem. Soc., 2016, 138(30): 9385.

[32] Huo HY, Wu B, Zhang T, Zheng XS, Ge L, Xu TW, Guo XX, Sun XL. Anion-immobilized polymer electrolyte achieved by cationic metal-organic framework filler for dendrite-free solid-state batteries. Energy Storage Mater., 2019, 18, 59.

[33] Kerman K, Luntz A, Viswanathan V, Chiang YM, Chen ZB. Review—Practical challenges hindering the development of solid state Li ion batteries. J. Electrochem. Soc., 2017, 164(7): A1731.

[34] Berhaut CL, Dedryvère R, Timperman L, Schmidt G, Lemordant D, Anouti M. A new solvent mixture for use of LiTDI as electrolyte salt in Li-ion batteries. Electrochim. Acta, 2019, 305, 534.

[35] Liu KW, Cheng CF, Zhou LY, Zou F, Liang WF, Wang MY, Zhu Y. A shear thickening fluid based impact resistant electrolyte for safe Li-ion batteries. J. Power Sources, 2019, 423, 297.

[36] Cheng XB, Zhao CZ, Yao YX, Liu H, Zhang Q. Recent advances in energy chemistry between solid-state electrolyte and safe lithium-metal anodes. Chem, 2019, 5(1): 74.

[37] Zhang SJ, You JH, Chen JD, Hu YY, Wang CW, Liu Q, Li YY, Zhou Y, Li JT, Šwiatowska J, Huang L, Sun SG. Aluminum-based metal-organic frameworks derived Al₂O₃-loading mesoporous carbon as a host matrix for lithium-metal anodes. ACS Appl. Mater. Interfaces, 2019, 11(51): 47939.

[38] M.Q. Zhu, B. Li, S.M. Li, Z.G. Du, Y.J. Gong, and S.B. Yang, Dendrite-free metallic lithium in lithiophilic carbonized metal-organic frameworks, Adv. Energy Mater., 8(2018), No. 18, art. No. 1703505.

[39] Ban XY, Zhang WQ, Chen N, Sun CW. A high-performance and durable poly(ethylene oxide)-based composite solid electrolyte for all solid-state lithium battery. J. Phys. Chem. C, 2018, 122(18): 9852.

[40] Cho YH, Wolfenstine J, Rangasamy E, Kim H, Choe H, Sakamoto J. Mechanical properties of the solid Li-ion conducting electrolyte: Li_0.33La_0.57TiO₃. J. Mater. Sci., 2012, 47(16): 5970.

[41] Miura A, Rosero-Navarro NC, Sakuda A, Tadanaga K, Phuc NHH, Matsuda A, Machida N, Hayashi A, Tatsumisago M. Liquid-phase syntheses of sulfide electrolytes for all-solid-state lithium battery. Nat. Rev. Chem., 2019, 3(3): 189.

[42] Zhao N, Khokhar W, Bi ZJ, Shi C, Guo XX, Fan LZ, Nan CW. Solid garnet batteries. Joule, 2019, 3(5): 1190.

[43] L. Fan, S.Y. Wei, S.Y. Li, Q. Li, and Y.Y. Lu, Recent progress of the solid-state electrolytes for high-energy metal-based batteries, Adv. Energy Mater., 8(2018), No. 11, art. No. 1702657.

[44] M. Shoji, E.J. Cheng, T. Kimura, and K. Kanamura, Recent progress for all solid state battery using sulfide and oxide solid electrolytes, J. Phys. D: Appl. Phys., 52(2019), No. 10, art. No. 103001.

[45] Yokokawa H. Thermodynamic stability of sulfide electrolyte/oxide electrode interface in solid-state lithium batteries. Solid State Ionics, 2016, 285, 126.

[46] J. Ko, D.H. Cho, D.J. Kim, and Y.S. Yoon, Suppression of formation of lithium dendrite via surface modification by 2-D lithium phosphorous oxynitride as a highly stable anode for metal lithium batteries, J. Alloys Compd., 845(2020), art. No. 156280.

[47] Q.B. Zhang, Z.L. Gong, and Y. Yang, Advance in interface and characterizations of sulfide solid electrolyte materials, Acta Phys. Sin., 69(2020), No. 22, art. No. 228803.

[48] Adachi GY, Imanaka N, Aono H. Fast Li⁺ conducting ceramic electrolytes. Adv. Mater., 1996, 8(2): 127.

[49] Aono H, Sugimoto E, Sadaoka Y, Imanaka N, Adachi GY. Ionic conductivity of solid electrolytes based on lithium titanium phosphate. J. Electrochem. Soc., 1990, 137(4): 1023.

[50] Li YT, Zhou WD, Chen X, Lü XJ, Cui ZM, Xin S, Xue LG, Jia QX, Goodenough JB. Mastering the interface for advanced all-solid-state lithium rechargeable batteries. PNAS, 2016, 113(47): 13313.

[51] Thangadurai V, Narayanan S, Pinzaru D. Garnet-type solid-state fast Li ion conductors for Li batteries: Critical review. Chem. Soc. Rev., 2014, 43(13): 4714.

[52] Kim S, Hirayama M, Suzuki K, Kanno R. Hetero-epitaxial growth of Li_0.17La_0.61TiO₃ solid electrolyte on LiMn₂O₄ electrode for all solid-state batteries. Solid State Ionics, 2014, 262, 578.

[53] Zhao YS, Daemen LL. Superionic conductivity in lithium-rich anti-perovskites. J. Am. Chem. Soc., 2012, 134(36): 15042.

[54] Li YT, Zhou WD, Xin S, Li S, Zhu JL, Lü XJ, Cui ZM, Jia QX, Zhou JS, Zhao YS, Goodenough JB. Fluorine-doped antiperovskite electrolyte for all-solid-state lithium-ion batteries. Angew. Chem. Int. Ed., 2016, 55(34): 9965.

[55] Murugan R, Thangadurai V, Weppner W. Lithium ion conductivity of Li_5+xBa_xLa_3−xTa₂O₁₂ (x=0–2) with garnet-related structure in dependence of the barium content. Ionics, 2007, 13(4): 195.

[56] Kotobuki M, Munakata H, Kanamura K, Sato Y, Yoshida T. Compatibility of Li₇La₃Zr₂O₁₂ solid electrolyte to all-solid-state battery using Li metal anode. J. Electrochem. Soc., 2010, 157(10): A1076.

[57] Awaka J, Takashima A, Kataoka K, Kijima N, Idemoto Y, Akimoto J. Crystal structure of fast lithium-ion-conducting cubic Li₇La₃Zr₂O₁₂. Chem. Lett., 2011, 40(1): 60.

[58] Sun CW, Liu J, Gong YD, Wilkinson DP, Zhang JJ. Recent advances in all-solid-state rechargeable lithium batteries. Nano Energy, 2017, 33, 363.

[59] Zhang QQ, Liu K, Ding F, Liu XJ. Recent advances in solid polymer electrolytes for lithium batteries. Nano Res., 2017, 10(12): 4139.

[60] Kudu U, Famprikis T, Fleutot B, Braida MD, Le Mercier T, Islam MS, Masquelier C. A review of structural properties and synthesis methods of solid electrolyte materials in the Li₂S-P₂S₅ binary system. J. Power Sources, 2018, 407, 31.

[61] Zhang ZX, Zhang L, Yan XL, Wang HQ, Liu YY, Yu C, Cao XT, van Eijck L, Wen B. All-in-one improvement toward Li₆PS₅Br-based solid electrolytes triggered by compositional tune. J. Power Sources, 2019, 410–411, 162.

[62] Kamaya N, Homma K, Yamakawa Y, Hirayama M, Kanno R, Yonemura M, Kamiyama T, Kato Y, Hama S, Kawamoto K, Mitsui A. A lithium superionic conductor. Nat. Mater., 2011, 10(9): 682.

[63] Zhu M, Wu JX, Wang Y, Song MM, Long L, Siyal SH, Yang XP, Sui G. Recent advances in gel polymer electrolyte for high-performance lithium batteries. J. Energy Chem., 2019, 37, 126.

[64] Chan CK, Yang T, Weller JM. Nanostructured garnet-type Li₇La₃Zr₂O₁₂: Synthesis, properties, and opportunities as electrolytes for Li-ion batteries. Electrochim. Acta, 2017, 253, 268.

[65] Yoon SA, Oh NR, Yoo AR, Lee HG, Lee HC. Preparation and characterization of Ta-substituted Li₇La₃Zr_2−xO₁₂ garnet solid electrolyte by sol-gel processing. J. Korean Ceram. Soc., 2017, 54(4): 278.

[66] Li YQ, Wang Z, Li CL, Cao Y, Guo XX. Densification and ionic-conduction improvement of lithium garnet solid electrolytes by flowing oxygen sintering. J. Power Sources, 2014, 248, 642.

[67] Yu N, Shao CL, Liu YC, Guan HY, Yang XH. Nanofibers of LiMn₂O₄ by electrospinning. J. Colloid Interface Sci., 2005, 285(1): 163.

[68] Yang T, Gordon ZD, Li Y, Chan CK. Nanostructured garnet-type solid electrolytes for lithium batteries: Electrospinning synthesis of Li₇La₃Zr₂O₁₂ nanowires and particle size-dependent phase transformation. J. Phys. Chem. C, 2015, 119(27): 14947.

[69] Van Opdenbosch D, Zollfrank C. Cellulose-based biotemplated silica structuring. Adv. Eng. Mater., 2014, 16(6): 699.

[70] Gordon ZD, Yang T, Gomes Morgado GB, Chan CK. Preparation of nano- and microstructured garnet Li₇La₃Zr₂O₁₂ solid electrolytes for Li-ion batteries via cellulose templating. ACS Sustainable Chem. Eng., 2016, 4(12): 6391.

[71] N. Bernstein, M.D. Johannes, and K. Hoang, Origin of the structural phase transition in Li₇La₃Zr₂O₁₂, Phys. Rev. Lett., 109(2012), No. 20, art. No. 205702.

[72] Awaka J, Kijima N, Hayakawa H, Akimoto J. Synthesis and structure analysis of tetragonal Li₇La₃Zr₂O₁₂ with the garnet-related type structure. J. Solid State Chem., 2009, 182(8): 2046.

[73] Murugan R, Thangadurai V, Weppner W. Fast lithium ion conduction in garnet-type Li₇La₃Zr₂O₁₂. Angew. Chem. Int. Ed., 2007, 46(41): 7778.

[74] Wu JF, Pang WK, Peterson VK, Wei L, Guo X. Garnet-type fast Li-ion conductors with high ionic conductivities for all-solid-state batteries. ACS Appl. Mater. Interfaces, 2017, 9(14): 12461.

[75] Du FM, Zhao N, Li YQ, Chen C, Liu ZW, Guo XX. All solid state lithium batteries based on lamellar garnet-type ceramic electrolytes. J. Power Sources, 2015, 300, 24.

[76] Krauskopf T, Hartmann H, Zeier WG, Janek J. Toward a fundamental understanding of the lithium metal anode in solid-state batteries—An electrochemo-mechanical study on the garnet-type solid electrolyte Li_6.25Al_0.25La₃Zr₂O₁₂. ACS Appl. Mater. Interfaces, 2019, 11(15): 14463.

[77] Rosero-Navarro NC, Yamashita T, Miura A, Higuchi M, Tadanaga K. Effect of sintering additives on relative density and Li-ion conductivity of Nb-doped Li₇La₃ZrO₁₂ solid electrolyte. J. Am. Ceram. Soc., 2017, 100(1): 276.

[78] Song SD, Chen BT, Ruan YL, Sun J, Yu LM, Wang Y, Thokchom J. Gd-doped Li₇La₃Zr₂O₁₂ garnet-type solid electrolytes for all-solid-state Li-ion batteries. Electrochim. Acta, 2018, 270, 501.

[79] Rettenwander D, Geiger CA, Amthauer G. Synthesis and crystal chemistry of the fast Li-ion conductor Li₇La₃Zr₂O₁₂ doped with Fe. Inorg. Chem., 2013, 52(14): 8005.

[80] Bernuy-Lopez C, Manalastas W, del Amo JML, Aguadero A, Aguesse F, Kilner JA. Atmosphere controlled processing of Ga-substituted garnets for high Li-ion conductivity ceramics. Chem. Mater., 2014, 26(12): 3610.

[81] Quinzeni I, Capsoni D, Berbenni V, Mustarelli P, Sturini M, Bini M. Stability of low-temperature Li₇La₃Zr₂O₁₂ cubic phase: The role of temperature and atmosphere. Mater. Chem. Phys., 2017, 185, 55.

[82] Kotobuki M, Kanamura K, Sato Y, Yoshida T. Fabrication of all-solid-state lithium battery with lithium metal anode using Al₂O₃-added Li₇La₃Zr₂O₁₂ solid electrolyte. J. Power Sources, 2011, 196(18): 7750.

[83] Kobi S, Mukhopadhyay A. Structural (in)stability and spontaneous cracking of Li-La-zirconate cubic garnet upon exposure to ambient atmosphere. J. Eur. Ceram. Soc., 2018, 38(14): 4707.

[84] Thangadurai V, Pinzaru D, Narayanan S, Baral AK. Fast solid-state Li ion conducting garnet-type structure metal oxides for energy storage. J. Phys. Chem. Lett., 2015, 6(2): 292.

[85] F.D. Han, Y.Z. Zhu, X.F. He, Y.F. Mo, and C.S. Wang, Electrochemical stability of Li₁₀GeP₂S₁₂ and Li₇La₃Zr₂O₁₂ solid electrolytes, Adv. Energy Mater., 6(2016), No. 8, art. No. 1501590.

[86] Zhu YZ, He XF, Mo YF. Origin of outstanding stability in the lithium solid electrolyte materials: Insights from thermodynamic analyses based on first-principles calculations. ACS Appl. Mater. Interfaces, 2015, 7(42): 23685.

[87] Duan HN, Zheng HP, Zhou Y, Xu BY, Liu HZ. Stability of garnet-type Li ion conductors: An overview. Solid State Ionics, 2018, 318, 45.

[88] Dumon A, Huang M, Shen Y, Nan CW. High Li ion conductivity in strontium doped Li₇La₃Zr₂O₁₂ garnet. Solid State Ionics, 2013, 243, 36.

[89] Cao SY, Song SB, Xiang X, Hu Q, Zhang C, Xia ZW, Xu YH, Zha WP, Li JY, Gonzale PM, Han YH, Chen F. Modeling, preparation, and elemental doping of Li₇La₃Zr₂O₁₂ garnet-type solid electrolytes: A review. J. Korean Ceram. Soc., 2019, 56(2): 111.

[90] Ramakumar S, Satyanarayana L, Manorama SV, Murugan R. Structure and Li⁺ dynamics of Sb-doped Li₇La₃Zr₂O₁₂ fast lithium ion conductors. Phys. Chem. Chem. Phys., 2013, 15(27): 11327.

[91] Hu ZL, Liu HD, Ruan HB, Hu R, Su YY, Zhang L. High Li-ion conductivity of Al-doped Li₇La₃Zr₂O₁₂ synthesized by solid-state reaction. Ceram. Int., 2016, 42(10): 12156.

[92] Im C, Park D, Kim H, Lee J. Al-incorporation into Li₇La₃Zr₂O₁₂ solid electrolyte keeping stabilized cubic phase for all-solid-state Li batteries. J. Energy Chem., 2018, 27(5): 1501.

[93] Li YQ, Wang Z, Cao Y, Du FM, Chen C, Cui ZH, Guo XX. W-doped Li₇La₃Zr₂O₁₂ ceramic electrolytes for solid state Li-ion batteries. Electrochim. Acta, 2015, 180, 37.

[94] Shimonishi Y, Toda A, Zhang T, Hirano A, Imanishi N, Yamamoto O, Takeda Y. Synthesis of garnet-type Li_7−xLa₃Zr₂O_12−1/2x and its stability in aqueous solutions. Solid State Ionics, 2011, 183(1): 48.

[95] Wang XS, Liu J, Yin R, Xu YC, Cui YH, Zhao L, Yu XB. High lithium ionic conductivity of garnet-type oxide Li_7+xLa₃Zr_2−xSm_xO₁₂ (x=0–0.1) ceramics. Mater. Lett., 2018, 231, 43.

[96] Gai JL, Zhao EQ, Ma FR, Sun DY, Ma XD, Jin YC, Wu QL, Cui YJ. Improving the Li-ion conductivity and air stability of cubic Li₇La₃Zr₂O₁₂ by the co-doping of Nb, Y on the Zr site. J. Eur. Ceram. Soc., 2018, 38(4): 1673.

[97] Monroe C, Newman J. The impact of elastic deformation on deposition kinetics at lithium/polymer interfaces. J. Electrochem. Soc., 2005, 152(2): A396.

[98] Yu S, Schmidt RD, Garcia-Mendez R, Herbert E, Dudney NJ, Wolfenstine JB, Sakamoto J, Siegel DJ. Elastic properties of the solid electrolyte Li₇La₃Zr₂O₁₂ (LLZO). Chem. Mater., 2016, 28(1): 197.

[99] Tsai CL, Dashjav E, Hammer EM, Finsterbusch M, Tietz F, Uhlenbruck S, Buchkremer HP. High conductivity of mixed phase Al-substituted Li₇La₃Zr₂O₁₂. J. Electroceram., 2015, 35(1–4): 25.

[100] Huang M, Dumon A, Nan CW. Effect of Si, In and Ge doping on high ionic conductivity of Li₇La₃Zr₂O₁₂. Electrochem. Commun., 2012, 21, 62.

[101] Li YT, Han JT, Wang CA, Xie H, Goodenough JB. Optimizing Li⁺ conductivity in a garnet framework. J. Mater. Chem, 2012, 22(30): 15357.

[102] Meesala Y, Liao YK, Jena A, Yang NH, Pang WK, Hu SF, Chang H, Liu CE, Liao SC, Chen JM, Guo XX, Liu RS. An efficient multi-doping strategy to enhance Li-ion conductivity in the garnet-type solid electrolyte Li₇La₃Zr₂O₁₂. J. Mater. Chem. A, 2019, 7(14): 8589.

[103] Bonizzoni S, Ferrara C, Berbenni V, Anselmi-Tamburini U, Mustarelli P, Tealdi C. NASICON-type polymer-in-ceramic composite electrolytes for lithium batteries. Phys. Chem. Chem. Phys., 2019, 21(11): 6142.

[104] Zheng J, Hu YY. New insights into the compositional dependence of Li-ion transport in polymer-ceramic composite electrolytes. ACS Appl. Mater. Interfaces, 2018, 10(4): 4113.

[105] Chen F, Zha WP, Yang DJ, Cao SY, Shen Q, Zhang LM, Sadoway DR. All-solid-state lithium battery fitted with polymer electrolyte enhanced by solid plasticizer and conductive ceramic filler. J. Electrochem. Soc., 2018, 165(14): A3558.

[106] Quartarone E, Mustarelli P. Electrolytes for solid-state lithium rechargeable batteries: Recent advances and perspectives. Chem. Soc. Rev., 2011, 40(5): 2525.

[107] Zhang WQ, Nie JH, Li F, Wang ZL, Sun CW. A durable and safe solid-state lithium battery with a hybrid electrolyte membrane. Nano Energy, 2018, 45, 413.

[108] T.L. Jiang, P.G. He, G.X. Wang, Y. Shen, C.W. Nan, and L.Z. Fan, Lithium batteries: Solvent-free synthesis of thin, flexible, nonflammable garnet-based composite solid electrolyte for all-solid-state lithium batteries, Adv. Energy Mater., 10(2020), No. 12, art. No. 1903376.

[109] Le HTT, Ngo DT, Kalubarme RS, Cao GZ, Park CN, Park CJ. Composite gel polymer electrolyte based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) with modified aluminum-doped lithium lanthanum titanate (ALLTO) for high-performance lithium rechargeable batteries. ACS Appl. Mater. Interfaces, 2016, 8(32): 20710.

[110] Pitillas Martinez AI, Aguesse F, Otaegui L, Schneider M, Roters A, Llordés A, Buannic L. The cathode composition, a key player in the success of Li-metal solid-state batteries. J. Phys. Chem. C, 2019, 123(6): 3270.

[111] Stergiopoulos T, Arabatzis IM, Katsaros G, Falaras P. Binary polyethylene oxide/titania solid-state redox electrolyte for highly efficient nanocrystalline TiO₂ photoelectrochemical cells. Nano Lett., 2002, 2(11): 1259.

[112] Choi SW, Jo SM, Lee WS, Kim YR. An electrospun poly(vinylidene fluoride) nanofibrous membrane and its battery applications. Adv. Mater., 2003, 15(23): 2027.

[113] Wang HP, Huang HT, Wunder SL. Novel microporous poly(vinylidene fluoride) blend electrolytes for lithium-ion batteries. J. Electrochem. Soc., 2000, 147(8): 2853.

[114] Jeddi K, Ghaznavi M, Chen P. A novel polymer electrolyte to improve the cycle life of high performance lithium-sulfur batteries. J. Mater. Chem. A, 2013, 1(8): 2769.

[115] Jiang GX, Maeda S, Yang HB, Saito Y, Tanase S, Sakai T. All solid-state lithium-polymer battery using poly(urethane acrylate)/nano-SiO₂ composite electrolytes. J. Power Sources, 2005, 141(1): 143.

[116] Raghavan P, Manuel J, Zhao XH, Kim DS, Ahn JH, Nah C. Preparation and electrochemical characterization of gel polymer electrolyte based on electrospun polyacrylonitrile nonwoven membranes for lithium batteries. J. Power Sources, 2011, 196(16): 6742.

[117] Zheng J, Tang MX, Hu YY. Lithium ion pathway within Li₇La₃Zr₂O₁₂-polyethylene oxide composite electrolytes. Angew. Chem. Int. Ed, 2016, 55(40): 12538.

[118] Brogioli D, Langer F, Kun R, Mantia FL. Space-charge effects at the Li₇La₃Zr₂O₁₂/poly(ethylene oxide) interface. ACS Appl. Mater. Interfaces, 2019, 11(12): 11999.

[119] Jeong K, Park S, Lee SY. Revisiting polymeric single lithium-ion conductors as an organic route for all-solid-state lithium ion and metal batteries. J. Mater. Chem. A, 2019, 7(5): 1917.

[120] Liu W, Liu N, Sun J, Hsu PC, Li YZ, Lee HW, Cui Y. Ionic conductivity enhancement of polymer electrolytes with ceramic nanowire fillers. Nano Lett., 2015, 15(4): 2740.

[121] Zhu YH, Cao J, Chen H, Yu QP, Li BH. High electrochemical stability of a 3D cross-linked network PEO@nano-SiO₂ composite polymer electrolyte for lithium metal batteries. J. Mater. Chem. A, 2019, 7(12): 6832.

[122] Chen L, Li YT, Li SP, Fan LZ, Nan CW, Goodenough JB. PEO/garnet composite electrolytes for solidstate lithium batteries: From “ceramic-in-polymer” to “polymer-in-ceramic”. Nano Energy, 2018, 46, 176.

[123] Christie AM, Lilley SJ, Staunton E, Andreev YG, Bruce PG. Increasing the conductivity of crystalline polymer electrolytes. Nature, 2005, 433(7021): 50.

[124] Agapov AL, Sokolov AP. Decoupling ionic conductivity from structural relaxation: A way to solid polymer electrolytes?. Macromolecules, 2011, 44(11): 4410.

[125] Yang CC, Lian ZY, Lin SJ, Shih JY, Chen WH. Preparation and application of PVDF-HFP composite polymer electrolytes in LiNi_0.5Co_0.2Mn_0.3O₂ lithium-polymer batteries. Electrochim. Acta, 2014, 134, 258.

[126] Jiang YX, Chen ZF, Zhuang QC, Xu JM, Dong QF, Huang L, Sun SG. A novel composite microporous polymer electrolyte prepared with molecule sieves for Li-ion batteries. J. Power Sources, 2006, 160(2): 1320.

[127] Li Y, Zhang W, Dou QQ, Wong KW, Ng KM. Li₇La₃Zr₂O₁₂ ceramic nanofiber-incorporated composite polymer electrolytes for lithium metal batteries. J. Mater. Chem. A, 2019, 7(7): 3391.

[128] Lu J, Liu YC, Yao PH, Ding ZY, Tang QM, Wu JW, Ye ZR, Huang K, Liu XJ. Hybridizing poly(vinylidene fluoride-co-hexafluoropropylene) with Li_6.5La₃Zr_1.5Ta_0.5O₁₂ as a lithium-ion electrolyte for solid state lithium metal batteries. Chem. Eng. J., 2019, 367, 230.

[129] Langer F, Palagonia MS, Bardenhagen I, Glenneberg J, Mantia FL, Kun R. Impedance spectroscopy analysis of the lithium ion transport through the Li₇La₃Zr₂O₁₂/P(EO)₂₀Li interface. J. Electrochem. Soc., 2017, 164(12): A2298.

[130] Wei T, Zhang ZH, Wang ZM, Zhang Q, Ye YS, Lu JH, Rahman ZU, Zhang ZW. Ultrathin solid composite electrolyte based on Li_6.4La₃Zr_1.4Ta_0.6O₁₂/PVDF-HFP/LiTFSI/succinonitrile for high-performance solid-state lithium metal batteries. ACS Appl. Energy Mater., 2020, 3(9): 9428.

[131] Aravindan V, Vickraman P, Sivashanmugam A, Thirunakaran R, Gopukumar S. Comparison among the performance of LiBOB, LiDFOB and LiFAP impregnated polyvinylidenefluoride-hexafluoropropylene nanocomposite membranes by phase inversion for lithium batteries. Curr. Appl. Phys., 2013, 13(1): 293.

[132] Gnanaraj JS, Zinigrad E, Levi MD, Aurbach D, Schmidt M. A comparison among LiPF₆, LiPF₃(CF₂CF₃)₃ (Li-FAP), and LiN(SO₂CF₂CF₃)₂ (LiBETI) solutions: Electrochemical and thermal studies. J. Power Sources, 2003, 119–121, 799.

[133] Sloop SE, Pugh JK, Wang S, Kerr JB, Kinoshita K. Chemical reactivity of PF₅ and LiPF₆ in ethylene carbonate/dimethyl carbonate solutions, Electrochem. Solid-State Lett., 2001, 4(4): A42.

[134] Chen RJ, Liu F, Chen Y, Ye YS, Huang YX, Wu F, Li L. An investigation of functionalized electrolyte using succinonitrile additive for high voltage lithium-ion batteries. J. Power Sources, 2016, 306, 70.

[135] Das S, Mitra S, Combet J, Mukhopadhyay R, Bhattacharyya AJ. Study of solvent relaxation of pristine succinonitrile and succinonitrile-salt mixtures using quasielastic neutron scattering. Solid State Ionics, 2015, 279, 72.

[136] Larraz G, Orera A, Sanjuán ML. Cubic phases of garnet-type Li₇La₃Zr₂O₁₂: The role of hydration. J. Mater. Chem. A, 2013, 1(37): 11419.

[137] Jin Y, McGinn PJ. Li₇La₃Zr₂O₁₂ electrolyte stability in air and fabrication of a Li/Li₇La₃Zr₂O₁₂/Cu_0.1V₂O₅ solid-state battery. J. Power Sources, 2013, 239, 326.

[138] Sharafi A, Yu S, Naguib M, Lee M, Ma C, Meyer HM, Nanda J, Chi M, Siegel DJ, Sakamoto J. Impact of air exposure and surface chemistry on Li-Li₇La₃Zr₂O₁₂ interfacial resistance. J. Mater. Chem. A, 2017, 5(26): 13475.

[139] Cheng L, Crumlin EJ, Chen W, Qiao RM, Hou HM, Lux SF, Zorba V, Russo R, Kostecki R, Liu Z, Persson K, Yang WL, Cabana J, Richardson T, Chen GY, Doeff M. The origin of high electrolyte-electrode interfacial resistances in lithium cells containing garnet type solid electrolytes. Phys. Chem. Chem. Phys., 2014, 16(34): 18294.

[140] Cheng L, Wu CH, Jarry A, Chen W, Ye YF, Zhu JF, Kostecki R, Persson K, Guo JH, Salmeron M, Chen GY, Doeff M. Interrelationships among grain size, surface composition, air stability, and interfacial resistance of Al-substituted Li₇La₃Zr₂O₁₂ solid electrolytes. ACS Appl. Mater. Interfaces, 2015, 7(32): 17649.

[141] Li YT, Chen X, Dolocan A, Cui ZM, Xin S, Xue LG, Xu HH, Park K, Goodenough JB. Garnet electrolyte with an ultralow interfacial resistance for Li-metal batteries. J. Am. Chem. Soc., 2018, 140(20): 6448.

[142] Wei T, Zhang ZH, Zhu ZY, Zhou XP, Wang YY, Wang YZ, Zhuang QC. Recycling of waste plastics and scalable preparation of Si/CNF/C composite as anode material for lithium-ion batteries. Ionics, 2019, 25(4): 1523.

[143] Sharafi A, Kazyak E, Davis AL, Yu S, Thompson T, Siegel DJ, Dasgupta NP, Sakamoto J. Surface chemistry mechanism of ultra-low interfacial resistance in the solid-state electrolyte Li₇La₃Zr₂O₁₂. Chem. Mater., 2017, 29(18): 7961.

[144] Shen X, Cheng XB, Shi P, Huang JQ, Zhang XQ, Yan C, Li T, Zhang Q. Lithium-matrix composite anode protected by a solid electrolyte layer for stable lithium metal batteries. J. Energy Chem., 2019, 37, 29.

[145] W. Luo, Y.H. Gong, Y.Z. Zhu, Y.J. Li, Y.G. Yao, Y. Zhang, K. Fu, G. Pastel, C.F. Lin, Y.F. Mo, E.D. Wachsman, and L.B. Hu, Reducing interfacial resistance between garnet-structured solid-state electrolyte and Li-metal anode by a germanium layer, Adv. Mater., 29(2017), No. 22, art. No. 1606042.

[146] Park K, Yu BC, Jung JW, Li YT, Zhou WD, Gao HC, Son S, Goodenough JB. Electrochemical nature of the cathode interface for a solid-state lithium-ion battery: Interface between LiCoO₂ and garnet-Li₇La₃Zr₂O₁₂. Chem. Mater., 2016, 28(21): 8051.

[147] K. Yan, Z.D. Lu, H.W. Lee, F. Xiong, P.C. Hsu, Y.Z. Li, J. Zhao, S. Chu, and Y. Cui, Selective deposition and stable encapsulation of lithium through heterogeneous seeded growth, Nat. Energy, 1(2016), art. No. 16010.

[148] Ohta S, Kobayashi T, Seki J, Asaoka T. Electrochemical performance of an all-solid-state lithium ion battery with garnet-type oxide electrolyte. J. Power Sources, 2012, 202, 332.

[149] J. van den Broek, S. Afyon, and J.L.M. Rupp, Interface-engineered all-solid-state Li-ion batteries based on garnet-type fast Li+ conductors, Adv. Energy Mater., 6(2016), No. 19, art. No. 1600736.

[150] Raj R, Wolfenstine J. Current limit diagrams for dendrite formation in solid-state electrolytes for Li-ion batteries. J. Power Sources, 2017, 343, 119.

[151] Trybula M, Gancarz T, Gasior W, Pasturel A. Bulk and surface properties of liquid Al-Li and Li-Zn alloys. Metall. Mater. Trans. A, 2014, 45(12): 5517.

[152] J. Duan, W.Y. Wu, A.M. Nolan, T.R. Wang, J.Y. Wen, C.C. Hu, Y.F. Mo, W. Luo, and Y.H. Huang, Lithium-graphite paste: An interface compatible anode for solid-state batteries, Adv. Mater., 31(2019), No. 10, art. No. 1807243.

[153] C.W. Wang, H. Xie, L. Zhang, Y.H. Gong, G. Pastel, J.Q. Dai, B.Y. Liu, E.D. Wachsman, and L.B. Hu, Universal soldering of lithium and sodium alloys on various substrates for batteries, Adv. Energy Mater., 8(2018), No. 6, art. No. 1701963.

[154] Vardar G, Bowman WJ, Lu QY, Wang JY, Chater RJ, Aguadero A, Seibert R, Terry J, Hunt A, Waluyo I, Fong DD, Jarry A, Crumlin EJ, Hellstrom SL, Chiang YM, Yildiz B. Structure, chemistry, and charge transfer resistance of the interface between Li₇La₃Zr₂O₁₂ electrolyte and LiCoO₂ cathode. Chem. Mater., 2018, 30(18): 6259.

[155] Ohta S, Seki J, Yagi Y, Kihira Y, Tani T, Asaoka T. Co-sinterable lithium garnet-type oxide electrolyte with cathode for all-solid-state lithium ion battery. J. Power Sources, 2014, 265, 40.

[156] Thangadurai V, Weppner W. Investigations on electrical conductivity and chemical compatibility between fast lithium ion conducting garnet-like Li₆BaLa₂Ta₂O₁₂ and lithium battery cathodes. J. Power Sources, 2005, 142(1–2): 339.

[157] Han FD, Yue J, Chen C, Zhao N, Fan XL, Ma ZH, Gao T, Wang F, Guo XX, Wang CS. Interphase engineering enabled all-ceramic lithium battery. Joule, 2018, 2(3): 497.