Understanding the Positive Effect of LATP in Polymer Electrolytes in All-Solid-State Lithium Batteries

Abstract

Composite solid electrolytes with ceramic particles dispersed in a polymer matrix are considered a correct choice for all-solid-state batteries. These electrolytes balance the high ionic conductivity of superionic-ceramic conductors and the elasticity of polymers. Here, Li||LiFePO4 batteries with 30 wt% of LATP embedded in PEO20:LiTFSI show superior performance at elevated temperature. After ∼150 cycles, cells retained 84% of their original capacity compared to only 51% for batteries with no additive. At 5 C cells demonstrate 43% higher capacity. In symmetric cells with blocking and non-blocking electrodes and all-solid-state batteries LATP lowers the impedance of the electrode-electrolyte interface ensuring cycling stability. LATP improves performance by stabilization of the cathode-electrolyte interface, apparently the major contributor to the cell impedance.

Screen‐Printed Composite LiFePO4‐LLZO Cathodes Towards Solid‐State Li‐ion Batteries

“…Similarly, Zheng Zhang et al reported that the composite solid electrolytes (CSEs) used two different oxide fillers 10 wt% of LLZO and LLZTO ceramic filler offered the ionic conductivity of 1.7×10 −4 S cm −1 at 30 °C [33] . The cationic lithium transference number was investigated by Sorensen and Jacobsen method [34–36] . t Li+ value was 0.41 and 0.44 for CSE1 and CSE2, indicate almost no difference (Figure S4).…”

“…[33] The cationic lithium transference number was investigated by Sorensen and Jacobsen method. [34][35][36] t Li + value was 0.41 and 0.44 for CSE1 and CSE2, indicate almost no difference (Figure S4). The electrochemical stability of CSE is verified by LSV shown in Figure 2d.…”

A Novel Approach for Post-Mortem Analysis in All-Solid-State Batteries: Isolating Solid Polymer Electrolytes from Lithium Anodes

“…49 However, in the middle-high frequency range, the arc is not symmetric, which can be explained by a superposition of the resistance of a surface film (which forms at the Li-SPE interface) and the charge transfer process (i.e., Li → Li + + e − ). 15 Overall, the cell's interface resistance was seen to increase after cycling, most likely due to surface film formation.…”

“…Many polymeric electrolytes become amorphous only beyond their melting point (∼60 °C), leading to different and much faster conductance mechanisms compared to SPE behavior at low temperatures (readily seen by Arrhenius plots related to conductivity or resistance of SPEs). [14][15][16][17] The primary challenge for the practical and highly necessary postmortem analyses of ASSBs using spectroscopic tools is to separate between the lithium metal anode and the polymer electrolyte, thus being able to analyze authentic interfaces.…”