Functional additives for solid polymer electrolytes in flexible and high‐energy‐density solid‐state lithium‐ion batteries

Abstract

Solid polymer electrolytes (SPEs) have become increasingly attractive in solidstate lithium-ion batteries (SSLIBs) in recent years because of their inherent properties of flexibility, processability, and interfacial compatibility. However, the commercialization of SPEs remains challenging for flexible and highenergy-density LIBs. The incorporation of functional additives into SPEs could significantly improve the electrochemical and mechanical properties of SPEs and has created some historical milestones in boosting the development of SPEs. In this study, we review the roles of additives in SPEs, highlighting the working mechanisms and functionalities of the additives. The additives could afford significant advantages in boosting ionic conductivity, increasing ion transference number, improving high-voltage stability, enhancing mechanical strength, inhibiting lithium dendrite, and reducing flammability. Moreover, the application of functional additives in high-voltage cathodes, lithium-sulfur batteries, and flexible lithium-ion batteries is summarized. Finally, future research perspectives are proposed to overcome the unresolved technical hurdles and critical issues in additives of SPEs, such as facile fabrication process, interfacial compatibility, investigation of the working mechanism, and special functionalities.

Substantial Proton Ion Conduction in Methylcellulose/Pectin/Ammonium Chloride Based Solid Nanocomposite Polymer Electrolytes: Effect of ZnO Nanofiller

“…Whereas SPEs based on a single host polymer suffer from low ionic conductivity, polymer blending [ 10 ], incorporation of additives [ 11 ], polymer functionalization [ 12 ], and polymer crosslinking [ 13 ] are effective strategies to improve the performance of SPE systems. Specifically, polymer blending, a strategy of mixing two polymers to improve the amorphous phase of the polymer electrolyte systems, has been an excellent approach to improving the ionic conductivity of PEs.…”

Improving Cyclability of All‐Solid‐State Batteries via Stabilized Electrolyte–Electrode Interface with Additive in Poly(propylene carbonate) Based Solid Electrolyte

“…The relative intensity of the XRD peak at 2 θ ≈ 20° of the PPC‐TX SPE was lower than that of the original PPC because the amorphous nature and the degree of disorder of the PPC‐TX SPE film slightly increased with the addition of TEGDME. [ 38 , 39 ] The thermal stability of the SPE is important in terms of battery safety when it comes to high temperature. Thus, the thermal stabilities of the PPC‐TX films were determined for various contents of the TEGDME additive using thermogravimetric analysis (TGA) (Figure S4 , Supporting Information).…”

“…[ 11 ] This implied that, because of the increase in amorphous regions, the mobility of the PPC‐TX film increased significantly with increasing content of the TEGDME additive. [ 38 ]…”

Induction and Maintenance of Local Structural Durability for High‐Energy Nickel‐Rich Layered Oxides

“…Among the Ni‐rich cathodes for lithium‐ion batteries (LIBs) with high energy density and durable cycling capability, LiNi 0.8 Co 0.15 Al 0.05 O 2 (LNCA) is now receiving growing attention due to its high specific capacity (200 mAh g −1 ) and economic viability. [ 1 ] However, the drawbacks concerning structural instability, poor rate capability and inadequate cycle performance are still the huge obstacle for its further commercial utilization. One of the reasons is attributed to the Li + /Ni 2+ mixing phenomenon, caused by similar ion radii of Li + and Ni 2+ (0.76 and 0.69 Å), which seriously hinders the migration of Li + and increases the kinetics barrier for Li + diffusion, resulting in limited rate capability.…”