Flame-Retardant ADP/PEO Solid Polymer Electrolyte for Dendrite-Free and Long-Life Lithium Battery by Generating Al, P-rich SEI Layer

Abstract

The poly(ethylene oxide) solid polymer electrolyte (PEO SPE) has recently received much attention, however, the organic components in the SPE are still flammable. In this paper, we find that the high efficiency halogen-free aluminum (Al) diethyl hypophosphite flame retardant (ADP) is effective in reducing the flammability of PEO SPE. The SEI layer containing Al and phosphorus (P) inhibits the growth of lithium dendrite and enhances the cycle life of the battery. The capacity of a LiFePO 4 / SPE/Li battery containing ADP is still 123.2 mAh g −1 at 1.0 C and the Coulombic efficiency is as high as 99.95% after 1000 cycles (60 °C). At the same time, Al, P-rich SEI can inhibit the growth of lithium dendrite and the cycle stability of the battery is further enhanced.

Cyclodextrin-Integrated PEO-Based Composite Solid Electrolytes for High-Rate and Ultrastable All-Solid-State Lithium Batteries

“…These results can fully demonstrate that the high ionic conductivity, good mechanical strength, and superior electrochemical stability of the PEO–LiTFSI-15%β-CD CSE are the critical synergistic factors to enable the LiFePO 4 -based ASSLB to possess a high specific capacity, good rate performance, and excellent cycling stability. Figure d displays the comparison of electrochemical performances of LiFePO 4 -based ASSLBs, and it indicates that our assembled ASSLB using the commercial LiFePO 4 cathode material and the β-CD-integrated PEO-based CSE exhibits an advanced performance among the state-of-the-art LiFePO 4 -based ASSLBs, ,− especially in terms of long-term stability. Furthermore, the PEO–LiTFSI-15% β-CD CSE also demonstrates a better electrochemical performance than those of the PEO–LiTFSI SSE in all-solid-state lithium–sulfur batteries (ASSLSB) (Figure S20).…”

Strategies and characterization methods for achieving high performance PEO-based solid-state lithium-ion batteries

“…While the halogen product might be harmful to the environment, Hu et al introduced aluminum diethyl hypophosphite (ADP) into the PEO electrolyte. 81 ADP as a halogen-free and environmentally friendly flame retardant enables the self-extinguish ability by forming hypophosphite and other substances to prevent the combustion of PEO electrolytes.…”

Toward a New Generation of Fire‐Safe Energy Storage Devices: Recent Progress on Fire‐Retardant Materials and Strategies for Energy Storage Devices

“…In the condensed phase(Figure 2a), fire growth is sustained by continuous mass and heat transfer from the decomposition reactions of flammable components of energy storage devices such as the electrolytes during thermal runaway or volatiles released from polymer‐based separators or electrolytes during thermal decomposition. [ 59 ] Hence, the formation of a barrier layer on the surface of the flammable component of the energy device can effectively minimize the amount of thermal feedback that aids fire growth and spread in the device. This barrier layer is a physical layer with insulating character and thermal stability that is generated chemically on the surface via intumescence or fire retardant coating on the surface of the flammable component of the device during thermal decomposition.…”