•  
  •  
 

Corresponding Author

Feng Pan(panfeng@pkusz.edu.cn)

Abstract

Inorganic crystalline solid electrolytes exhibit exceptional room-temperature ionic conductivities, giving them the potential to enable all-solid-state lithium (Li) - ion batteries. Developing new high-performance electrolytes is one of the most critical challenges to realize solid-state batteries, which requires understanding how chemistry facilitates fast ionic conduction and what the Li-ion migration mechanism is in inorganic solid electrolytes. In this review, we aim to summarize recent fundamental research progress in Li-ion transport, including crystal structure, behavior of ion migration (i.e., single-ion jump and multi-ions cooperative migration), and the relationship between ion migration and microstructure.
Generally, ion transport in crystalline structure can be categorized into vacancy and non-vacancy mechanism. For Li-ion conduction, the migration can be achieved through single-ion hopping and collective diffusion mechanism. For single-ion hopping mechanism, the diffusivity is determined by the depth of potential well (activation energy) and lattice dynamics; whereas in the later mechanism Li-ion moving from high potential to low potential could partially offset the energy required for Li-ion moving from low potential to high potential. By studying the collective diffusion from the perspective of local structures, it is believed that collective diffusion in fast ion conductor originates from the local “dual Li-S/O” structure units, which can be characterized by the “nearest Li-Li distance”.
Next, the paradigm of ion transport in solids is summarized. It is pointed out that most ion conductors follow Meyer-Neldel rule, where the activation energy and pre-exponential factor are mutual compensating. As a result, a balance should be adapted between these two values to achieve high Li-ion conductivity. However, for some fast ion conductors, the relationship does not follow the Meyer-Neldel rule (i.e., anti-Meyer-Neldel rule). Therefore, the physical significance of anti-Meyer-Neldel rule should be understood to develop next-generation lithium ion conductors.
In the end, future perspectives and open questions are proposed to design and develop high-performance inorganic solid electrolytes.

Graphical Abstract

Keywords

solid-sate electrolytes, Li-ion transport mechanism, cooperative transport, structure-function relationship, Meyer-Neldel rule

Publication Date

2021-06-28

Online Available Date

2021-04-22

Revised Date

2021-04-19

Received Date

2021-02-01

References

[1] Zhang B K, Tan R, Yang L Y, Zheng J X, Zhang K C, Mo S J, Lin Z, Pan F. Mechanisms and properties of ion-transport in inorganic solid electrolytes[J]. Energy Storage Mater., 2018, 10: 139-159.

[2] Zhao Q, Stalin S, Zhao C Z, Archer L A. Designing solid-state electrolytes for safe, energy-dense batteries[J]. Nat. Rev. Mater., 2020, 5(3): 229-252.
doi: 10.1038/s41578-019-0165-5 URL

[3] Zheng Z, Weng M Y, Yang L Y, Hu Z X, Chen Z F, Pan F. Thermodynamically revealing the essence of order and disorder structures in layered cathode materials[J]. Chin. J. Struct. Chem., 2019, 38(12): 2020-2026.

[4] Yang L Y, Yang K, Zheng J X, Xu K, Amine K, Pan F. Harnessing the surface structure to enable high-performance cathode materials for lithium-ion batteries[J]. Chem. Soc. Rev., 2020, 49(14): 4667-4680.
doi: 10.1039/D0CS00137F URL

[5] Lu Y, Chen X, Zhao C Z, Zhang Q. Machine learning towards screening solid-state lithium ion conductors[J]. Chin. J. Struct. Chem., 2020, 39(1): 8-10.

[6] Bachman J C, Muy S, Grimaud A, Chang H H, Pour N, Lux S F, Paschos O, Maglia F, Lupart S, Lamp P, Giordano L, Shao-Horn Y. Inorganic solid-state electrolytes for lithium batteries: mechanisms and properties governing ion conduction[J]. Chem. Rev., 2016, 116(1): 140-162.
doi: 10.1021/acs.chemrev.5b00563 URL

[7] Strock L W. The crystal structure of high temperature iodine silver alpha-AgI[J]. Physik. Chem. B, 1934, 25: 441-459.

[8] Liu Z C, Fu W J, Payzant E A, Yu X, Wu Z L, Dudney N J, Kiggans J, Hong K L, Rondinone A J, Liang C D. Anomalous high ionic conductivity of nanoporous β-Li3PS4[J]. J. Am. Chem. Soc., 2013, 135(3): 975-978.
doi: 10.1021/ja3110895 URL

[9] Zhang B K, Yang L Y, Wang L W, Pan F. Cooperative transport enabling fast Li-ion diffusion in thio-LISICON Li10SiP2S12 solid electrolyte[J]. Nano Energy, 2019, 62: 844-852.
doi: 10.1016/j.nanoen.2019.05.085 URL

[10] Deiseroth H J, Kong S T, Eckert H, Vannahme J, Reiner C, Zai T, Schlosser M. Li6PS5X: A class of crystalline Li-rich solids with an unusually high Li+ mobility[J]. Angew. Chem. Int. Ed., 2008, 47(4): 755-758.
doi: 10.1002/(ISSN)1521-3773 URL

[11] Liu Q, Geng Z, Han C P, Fu Y Z, Li S, He Y B, Kang F Y, Li B H. Challenges and perspectives of garnet solid electrolytes for all solid-state lithium batteries[J]. J. Power Sources, 2018, 389: 120-134.
doi: 10.1016/j.jpowsour.2018.04.019 URL

[12] Zhang B K, Lin Z, Dong H F, Wang L W, Pan F. Revealing cooperative Li-ion migration in Li1+xAlxTi2-x (PO4)3 solid state electrolytes with high Al doping[J]. J. Mater. Chem. A, 2020, 8(1): 342-348.
doi: 10.1039/C9TA09770H URL

[13] Chen Y, Rangasamy E, Liang C D, An K. Origin of high Li+ conduction in doped Li7La3Zr2O12 garnets[J]. Chem. Mat., 2015, 27(16): 5491-5494.
doi: 10.1021/acs.chemmater.5b02521 URL

[14] Stramare S, Thangadurai V, Weppner W. Lithium lanthanum titanates: A review[J]. Chem. Mat., 2003, 15(21): 3974-3990.
doi: 10.1021/cm0300516 URL

[15] He X F, Zhu Y Z, Mo Y F. Origin of fast ion diffusion in super-ionic conductors[J]. Nat. Commun., 2017, 8: 15893.
doi: 10.1038/ncomms15893 URL

[16] Muy S, Bachman J C, Giordano L, Chang H H, Abernathy D L, Bansal D, Delaire O, Hori S, Kanno R, Maglia F, Lupart S, Lamp P, Shao-Horn Y. Tuning mobility and stability of lithium ion conductors based on lattice dynamics[J]. Energy Environ. Sci., 2018, 11(4): 850-859.
doi: 10.1039/C7EE03364H URL

[17] Zhang B K, Zhong J J, Zhang Y P, Yang L Y, Yang J L, Li S, Wang L W, Pan F, Lin Z. Discovering a new class of fluoride solid-electrolyte materials via screening the structural property of Li-ion sublattice[J]. Nano Energy, 2021, 79: 105407.
doi: 10.1016/j.nanoen.2020.105407 URL

[18] Zhang B K, Weng M Y, Lin Z, Feng Y C, Yang L Y, Wang L W, Pan F. Li-ion cooperative migration and oxy-sulfide synergistic effect in Li14P2Ge2S16-6xOx solid-state-electrolyte enables extraordinary conductivity and high stability[J]. Small, 2020, 16(11): 1906374.
doi: 10.1002/smll.v16.11 URL

[19] Zhang B K, Lin Z, Wang L W, Pan F. Achieving both high ionic conductivity and high interfacial stability with the Li2+xC1-x BxO3 solid-state electrolyte: design from theoretical calculations[J]. ACS Appl. Mater. Inter., 2020, 12(5): 6007-6014.
doi: 10.1021/acsami.9b22185 URL

[20] Park M, Zhang X, Chung M, Less G B, Sastry A M. A review of conduction phenomena in Li-ion batteries[J]. J. Power Sources, 2010, 195(24): 7904-7929.
doi: 10.1016/j.jpowsour.2010.06.060 URL

[21] Wang Y, Richards W D, Ong S P, Miara L J, Kim J C, Mo Y F, Ceder G. Design principles for solid-state lithium superionic conductors[J]. Nat. Mater., 2015, 14(10): 1026-1031.
doi: 10.1038/nmat4369 pmid: 26280225

[22] Rodger A R, Kuwano J, West A R. Li+ ion conducting γ solid solutions in the systems Li4XO4-Li3YO4: X=Si, Ge, Ti; Y=P, As, V; Li4XO4-LiZO2: Z=Al, Ga, Cr and Li4GeO4-Li2CaGeO4[J]. Solid State Ion., 1985, 15(3): 185-198.
doi: 10.1016/0167-2738(85)90002-5 URL

[23] Kraft M A, Culver S P, Calderon M, Böcher F, Krauskopf T, Senyshyn A, Dietrich C, Zevalkink A, Janek J, Zeier W G. Influence of lattice polarizability on the ionic conductivity in the lithium superionic argyrodites Li6PS5X (X = Cl, Br, I)[J]. J. Am. Chem. Soc., 2017, 139(31): 10909-10918.
doi: 10.1021/jacs.7b06327 URL

[24] He X F, Bai Q, Liu Y S, Nolan A M, Ling C, Mo Y F. Crystal structural framework of lithium super-ionic conductors[J]. Adv. Energy Mater., 2019, 9(43): 1902078.
doi: 10.1002/aenm.v9.43 URL

[25] Metselaar R, Oversluizen G. The meyer-neldel rule in semiconductors[J]. J. Solid State Chem., 1984, 55(3): 320-326.
doi: 10.1016/0022-4596(84)90284-6 URL

[26] Qian H. Entropy-enthalpy compensation: Conformational fluctuation and induced-fit[J]. J. Chem. Phys., 1998, 109(22): 10015-10017.

[27] Krauskopf T, Muy S, Culver S P, Ohno S, Delaire O, Shao-Horn Y, Zeier W G. Comparing the descriptors for investigating the influence of lattice dynamics on ionic transport using the superionic conductor Na3PS4-x Sex[J]. J. Am. Chem. Soc., 2018, 140(43): 14464-14473.
doi: 10.1021/jacs.8b09340 pmid: 30284822

[28] Almond D P, West A R. Entropy effects in ionic conductivity[J]. Solid State Ion., 1986, 18-19: 1105-1109.

[29] Ngai K L. Meyer-Neldel rule and anti Meyer-Neldel rule of ionic conductivity: Conclusions from the coupling model[J]. Solid State Ion., 1998, 105(1): 231-235.
doi: 10.1016/S0167-2738(97)00469-4 URL

[30] Di Stefano D, Miglio A, Robeyns K, Filinchuk Y, Lech-artier M, Senyshyn A, Ishida H, Spannenberger S, Prutsch D, Lunghammer S, Rettenwander D, Wilkening M, Roling B, Kato Y, Hautier G. Superionic diffusion through frustrated energy landscape[J]. Chem, 2019, 5(9): 2450-2460.
doi: 10.1016/j.chempr.2019.07.001

[31] Funke K, Banhatti R D, Wilmer D, Dinnebier R, Fitch A, Jansen M. Low-temperature phases of rubidium silver iodide: crystal structures and dynamics of the mobile silver ions[J]. J. Phys. Chem. A, 2006, 110(9): 3010-3016.
doi: 10.1021/jp054807v URL

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.