Safe and Energy-Dense Flexible Solid-State Lithium–Oxygen Battery with a Structured Three-Dimensional Polymer Electrolyte

Abstract

Solid-state lithium−oxygen batteries (SSLOBs) with high energy density and enhanced safety are promising for green energy storage but plagued by limited O 2 /Li + /e − triple-phase reaction zone and high internal resistance. Herein, we design and fabricate a novel SSLOB with an integrated cathode and electrolyte structure in which carbon nanotubes were uniformly coated by an in situ-formed hybrid polymer electrolyte (HPE). This interface engineering builds a three-dimensional hybrid electronic and ionic conductor with sufficient void spaces, which facilitates oxygen diffusion and product accommodation and contributes to a significant expansion of the triple-phase reaction zone. The HPE is prepared in situ from poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), trimethyl phosphate (TMP), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) via weak hydrogen bond interactions and shows a flame-resistant property and high electrochemical stability (until 5.4 V). More importantly, it exhibits both a high ionic conductivity (1.08 × 10 −3 S cm −1 ) and high lithium ion transference number (t Li + up to 0.73) at ambient temperature, promoting uniform Li deposition. In consequence, the battery displays a gravimetric energy density of 542.1 Wh kg −1 (calculated from the weight of the whole device), superior rate performance, and long cycle life (1000 cycles, 167 days). These systems may promote the practical application of SSLOBs in next-generation energy storage.

An Electrochemically Stable Polyester Fabric-reinforced Poly(methyl methacrylate) Gel Polymer Electrolyte for Solid-State Lithium–Oxygen Batteries

“…As the reference, the lithium-ion conductivity at 25 °C and activation energy of PVDF-HFP@PET GPE is determined to be 0.32 mS cm –1 and 0.25 eV, respectively (Figure S5a,b in the SI). The same activation energies of PVDF-HFP@PET GPE and PMMA@PET GPE indicate an identical kinetic of lithium-ion diffusion in the gel states Figure e and its inset are the current response of the Li/PMMA@PET GPE/Li symmetric cell under direct-current (DC) polarization and the EIS plots before and after polarization, respectively.…”

“…The same activation energies of PVDF-HFP@PET GPE and PMMA@PET GPE indicate an identical kinetic of lithium-ion diffusion in the gel states. 43 Figure 2e and its inset are the current response of the Li/PMMA@PET GPE/Li symmetric cell under direct-current (DC) polarization and the EIS plots before and after polarization, respectively. The lithium-ion transference number (t Li + ) of PMMA@PET GPE is calculated to be 0.5 according to eq 3.…”

Tailoring the interface of lithium metal batteries with an in situ formed gel polymer electrolyte

“…3d), which can slow down the decomposition of the electrolyte components on both the Li metal anode and oxygen cathode. 58…”

“…3d), which can slow down the decomposition of the electrolyte components on both the Li metal anode and oxygen cathode. 58 Furthermore, due to the highest HOMO (Fig. 4d), the c-PH 6 C 9 -GPE is supposed to oxidize on the carbon cathode, forming a layer of CEI lm with high molecular weight as that on the NCM622 cathode.…”

Fascinating Bifunctional Electrocatalytic Activity via a Mesoporous Structured FeMnO3@ZrO2 Matrix as an Efficient Cathode for Li–O2 Batteries

“…As a result, the intensity of the C–O peak was enhanced in the discharged electrode, and a peak corresponding to Li 2 CO 3 was evident. After being recharged, this peak progressively decreased in intensity and eventually vanished. − These findings demonstrate that the ZrO 2 @FeMnO 3 /GNS catalyst had a significant impact on encouraging the reversible breakdown of the Li 2 O 2 discharge products.…”