Progress of the Interface Design in All‐Solid‐State Li–S Batteries

Abstract

Lithium-sulfur (Li-S) batteries are one of the most promising next-generation battery types for their high energy density and low cost. On the other hand, safety issues and poor cyclability strongly limit practical application. Solidstate electrolytes (SSEs) can present as high ionic conductivity as aprotic electrolytes and eventually avoid the shuttle effect, which provides an ultimate solution for safe Li-S batteries with good cyclability. In this review, the recent achievements in all-solid-state Li-S batteries based on inorganic SSEs are summarized. Furthermore, the main attentions are paid to the interfaces, including metallic lithium|SSEs, SSEs|SSEs, and composite sulfur cathode|SSEs. The potential approaches to deal with these interfacial issues are proposed as well, such as composite SSEs with an asymmetric structure to enhance their compatibility with lithium anodes and sulfur cathodes, adding Li 2 O or LiF and increasing the densification to reduce the grain boundary resistance, and nanomaterials used to improve the kinetic process in cathode. Figure 3. Structures of several SSEs. a) Local structure phase diagram of Li 2 S:P 2 S 5 glass ceramics and the changes of anionic units with temperature and compositions. Only the 75Li 2 S:25P 2 S 5 glass consisting of orthothiophosphates presents good thermal stability. Reproduced with permission. [58]

Slurry‐Fabricable Li+‐Conductive Polymeric Binders for Practical All‐Solid‐State Lithium‐Ion Batteries Enabled by Solvate Ionic Liquids

“…[5][6][7][8][9][10][11][12] Despite the poor chemical stability (e.g., instability in atmospheric air and conventional polar solvents), sulfide solid electrolyte (SE) materials are highly promising to realize all-solid-state Li-ion or Li batteries (ASLBs) which may outperform conventional LIBs. [5,[13][14][15][16][17][18][19][20][21] Li + conductivities of several state-of-the-art sulfide Li + superionic conductors have reached ≈10 −2 S cm −1 at room temperature (Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 [13] : 2.5 × 10 −2 S cm −1 , Li 7 P 3 S 11 [22] : 1.7 × 10 −2 S cm −1 ), which is comparable to that of organic liquid electrolytes. [23] Moreover, sulfide SE materials show considerably low Young's modulus of ≈20 GPa, allowing to be sintered mechanically at room temperature.…”

Addressing Interfacial Issues in Liquid-Based and Solid-State Batteries by Atomic and Molecular Layer Deposition

“…57,60,61 However, there are three general challenges regarding the interface between SSEs and electrode materials, including mismatch, chemical reactions, and space charge effects. 60,62 These interfacial issues between SSEs and electrodes (both cathode and anode) critically impact the stability and lifetime of full cells. 56 Concerning the bulk SSEs, anode/SSE interfaces, and cathode/SSE interfaces, the specific challenges differ.…”

Intrinsic Lithiophilicity of Li–Garnet Electrolytes Enabling High‐Rate Lithium Cycling

“…However, The high interfacial impedance between SSE and electrodes have severely hindered the full‐cell development. The Li/garnet interface is particularly significant for the following reasons:3a,4b,5 1) garnet since its discovery has been regarded as stable toward Li, which eventually becomes one of its main advantages; 2) Li/garnet interface with low impedance and relative stability may enable battery systems based on new chemistry such as Li–air and Li–S batteries.…”