Recent Progress in Solid Electrolytes for Energy Storage Devices

Abstract

With the rapid advances in safe, flexible, and even stretchable electronic products, it is important to develop matching energy storage devices to more effectively power them. However, the use of conventional liquid electrolytes produces volatilization and leakage that are dangerous and requires strict packaging layers that are typically rigid. To this end, solid electrolytes that can overcome these problems have attracted increasing attention in recent decades. In this review article, three main types of solid electrolytes (i.e., inorganic, polymer, and composite electrolytes) are first described and compared in terms of their structures and properties. The advantages of solid electrolytes to make safe, flexible, stretchable, wearable, and self‐healing energy storage devices, including supercapacitors and batteries, are then discussed. The remaining challenges and possible directions are finally summarized to highlight future development in this field.

Li4.3AlS3.3Cl0.7: A Sulfide-Chloride Lithium Ion Conductor with a Highly Disordered Structure

“…In both 2D and 3D diffusion processes, Li mobility can be limited by either the absence of a vacancy in the Li2 site, or by a too high energy barrier to overcome. In Li4.3AlS3.3Cl0.7, the number of vacancies per Li2 octahedra is 0.356(2), which corresponds to ~4.2 vacancies per nm 3 . In comparison, in Li4.4Al0.4Ge0.6S4, the number of disordered vacancies is ~1.1 vacancies per nm 3 , 34 yet, it shows a higher conductivity, suggesting that the number of disordered vacancies is not the limiting factor Li mobility in Li4.3AlS3.3Cl0.7.…”

“…In Li4.3AlS3.3Cl0.7, the number of vacancies per Li2 octahedra is 0.356(2), which corresponds to ~4.2 vacancies per nm 3 . In comparison, in Li4.4Al0.4Ge0.6S4, the number of disordered vacancies is ~1.1 vacancies per nm 3 , 34 yet, it shows a higher conductivity, suggesting that the number of disordered vacancies is not the limiting factor Li mobility in Li4.3AlS3.3Cl0.7. We can therefore deduce that the activation energy involving O-T-O jumps in the octahedral layer is higher than in Li4.4Al0.4Ge0.6S4, and that this barrier is limiting conductivity.…”

“…Incredible progress in this direction has been made in recent years. [3][4][5] The room temperature lithium conductivity target of 10 -3 S•cm -1 has now been met in different families of materials, including, garnet type Li6.55+yGa0.15La3Zr2−yScyO12 (1.8 × 10 −3 S•cm −1 ), 6 glass-ceramic 70 Li2S -30 P2S5 (mol %) (1.7 × 10 −2 S•cm −1 ), 7 thio-LISICON Li9.54Si1.74P1.44S11.7Cl0.3 (2.5 × 10 −2 S•cm −1 ), 8 and Li3YBr6 (1.7 × 10 −3 S•cm −1 ). 9 However, these materials still suffer from limitations such as high production and device processing costs (oxides garnets), sensitivity to moisture and air (sulfides), poor compatibility to cathode materials (hydrides), and low oxidation potential (halides).…”

Stretchable Supercapacitors: From Materials and Structures to Devices

“…The electrolyte acts as a carrier which allows ions to move during charging and discharging. [33,34] The conductivity and decomposition voltage should be as high as possible. Nowadays, gel electrolytes with a certain elasticity are more commonly used.…”

Rechargeable Sodium‐Based Hybrid Metal‐Ion Batteries toward Advanced Energy Storage

“…[ 50,99 ] As a result, the poor transport properties at the electrode/electrolyte interface and sluggish ion solvation/de‐solvation have a significantly impact on the performance of HMIBs. [ 100 ] State‐of‐the‐art electrolyte technologies, such as film‐forming additives, [ 101 ] high‐concentration electrolytes [ 102 ] and solid polymer electrolytes [ 103 ] could be useful to address these problems in the future. Electrolytes with wide and stable electrochemical windows can increase the energy density and deliver enhanced rate capability and better cycling performance.…”