| 1. |
- Andersson, Edvin K. W., et al.
(author)
-
Initial SEI formation in LiBOB-, LiDFOB- and LiBF4-containing PEO electrolytes
- 2024
-
In: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 12:15, s. 9184-9199
-
Journal article (peer-reviewed)abstract
- A limiting factor for solid polymer electrolyte (SPE)-based Li-batteries is the functionality of the electrolyte decomposition layer that is spontaneously formed at the Li metal anode. A deeper understanding of this layer will facilitate its improvement. This study investigates three SPEs – polyethylene oxide:lithium tetrafluoroborate (PEO:LiBF4), polyethylene oxide:lithium bis(oxalate)borate (PEO:LiBOB), and polyethylene oxide:lithium difluoro(oxalato)borate (PEO:LiDFOB) – using a combination of electrochemical impedance spectroscopy (EIS), galvanostatic cycling, in situ Li deposition photoelectron spectroscopy (PES), and ab initio molecular dynamics (AIMD) simulations. Through this combination, the cell performance of PEO:LiDFOB can be connected to the initial SPE decomposition at the anode interface. It is found that PEO:LiDFOB had the highest capacity retention, which is correlated to having the least decomposition at the interface. This indicates that the lower SPE decomposition at the interface still creates a more effective decomposition layer, which is capable of preventing further electrolyte decomposition. Moreover, the PES results indicate formation of polyethylene in the SEI in cells based on PEO electrolytes. This is supported by AIMD that shows a polyethylene formation pathway through free-radical polymerization of ethylene.
|
|
| 2. |
- Bertoli, Luca, et al.
(author)
-
Combination of solid polymer electrolytes and lithiophilic zinc for improved plating/stripping efficiency in anode-free lithium metal solid-state batteries
- 2023
-
In: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 464
-
Journal article (peer-reviewed)abstract
- Anode-free lithium metal batteries and solid-state batteries represent some of the most promising alternatives to the current Li-ion technology. The possibility to reach high energy density, due to the exploitation of Li-metal plating/stripping and the elimination of excess anode material, motivate the interest at both academic and in-dustrial levels. Despite these favourable properties, the use of Li-metal has always been extremely challenging and inefficient. This becomes particularly relevant in anode-free systems where no excess of lithium is introduced in the cell. The efficiency and quality of the deposition process is therefore of utmost importance. To optimize the Li-metal plating process, a combination of solid polymer electrolytes and a lithiophilic metal is applied herein, using in situ deposition of a zinc interlayer from a PEO-based SPE to modify the Cu current collector. Im-provements in specific capacity, coulombic efficiency and cyclability with the addition of zinc as lithiophilic metal is verified in full anode-free solid-state Li-batteries, while plating/stripping in half-cell configuration provides additional insights into the relevant mechanisms. The exploitation of the in situ deposited lithiophilic layer reveals an innovative and practical optimization strategy for the future of anode-free solid-state batteries.
|
|
