Correlating Electrode–Electrolyte Interface and Battery Performance in Hybrid Solid Polymer Electrolyte‐Based Lithium Metal Batteries

Abstract

Solid polymer electrolytes (SPEs) are desirable in lithium metal batteries (LMBs) since they are nonflammable and show excellent lithium dendrite growth resistance. However, fabricating high performance polymer LMBs is still a grand challenge because of the complex battery system. In this work, a series of tailor-designed hybrid SPEs were used to prepare LMBs with a LiFePO 4 -based cathode. High performance LMBs with both excellent rate capability and long cycle life were obtained at 60 and 90 C. The well-controlled network structure in this series of hybrid SPEs offers a model system to study the relationship between the SPE properties and the LMB performance. We show that the cycle life of the polymer LMBs is closely correlated with the SPE|Li interface ionic conductivity, underscoring the importance of the solid electrolyte interface in LMB operation. LMB performance was further correlated with the molecular network structure.We anticipate that results from this study will shed light on designing SPEs for high performance LMB applications.

Co-spray printing of LiFePO4 and PEO-Li1.5Al0.5Ge1.5(PO4)3 hybrid electrodes for all-solid-state Li-ion battery applications

“…7 and 8, the relatively high capacity retention of the honeycomb electrode, especially the H-L electrode, is most likely related to the compliance provided throughout the electrode by the inter-layered hybrid PEO-LAGP electrolyte, which helped to ensure that electrode/electrolyte contact was maintained during the volume change of the LFP during intercalation/deintercalation cycles. 15,18 Overall, the solid-state LFP-based H-L electrode half cell performance was similar or better than previous reports, 29,[42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] as summarized in Table 1. In these prior studies, the fabrication of the electrode and fabrication of the electrolyte were separate, and were usually combined with post fabrication heating and drying as well as post-assembly processes to prepare cells.…”

2D MXene-containing polymer electrolytes for all-solid-state lithium metal batteries

“…Composite cathodes were prepared using LiFePO 4 as the active material. The previously reported polyhedral oligomeric silsesquioxane (POSS)-based cross-linked hybrid SPE (POSS-2PEG6K) was used as the binder, 6,56 and carbon black as the conductive phase. An active material to binder to conductive phase weight ratio of 60 : 32 : 8 was chosen.…”

Plasticized Hybrid Network Solid Polymer Electrolytes for Lithium‐Metal Batteries

“…Discharge specific capacities of 164 mAh g −1 was obtained during galvanostatic cycling with a rate of C/20, which is higher than that of the unplasticized SPE LMB at 60 °C, and is comparable to the value of the unplasticized cell run at 90 °C . Decreased specific capacities of 143 and 98 mAh g −1 were obtained when the charge/discharge rate was increased to C/5 and C/2, respectively.…”

“…In order to confirm the practical application of the polymer electrolytes, LiFePO 4 /Li batteries were assembled with 2k70 as the electrolyte and separator. The composite cathode that contains 60% LiFePO 4 was prepared as previous reported . All cells were galvanostatically cycled at 30 °C with different rates, where C/ x means a charge/discharge of the theoretical cathode capacity (C, 170 mAh g −1 for LiFePO 4 ) in x h. Figure a shows the typical charge and discharge profiles of the LMBs, and Figure b is the discharge specific capacities and Coulombic efficiency of the batteries as a function of the cycle number with different charge/discharge rates at 30 °C.…”

“…Synthesis of Crosslinked SPE Films : Plasticized samples with different PEG250 contents were prepared by incorporating PEG250 to the POSS‐4PEG2k (molar ratio of PEG:POSS = 4:1) network adapted from previous reports . Butylated hydroxytoluene (BHT) inhibitor from as purchased PEG250 was removed by aluminum oxide column chromatography.…”