Abstract
Li-graphite and Li-O2 cells were investigated to increase their capacity, similar to that reported for other Li-powder anode-based cells such as Li-V2O5, Li-LiV3O8, and Li-sulfur batteries. When a Li-powder anode was used instead of a Li-foil anode in a Li-graphite cell, there was an increase of approximately 8% in the discharge capacity at a 0.1C rate. In a Li-O2 cell, the Li-powder anode showed an enhancement capacity of approximately 20%, as well as improved cycle performance and lower discharge/charge overpotential compared to the Li-foil anode. To explain the enhanced capacity obtained using the Li-powder anode, the exchange current density and Li+ concentration gradient at the cathode surface were calculated using electrochemical methods such as linear sweep voltammetry and cyclic voltammetry. The Li powder caused an increase in the exchange current density, which enhanced the Li-ion concentration gradient at the surface of the cathode. Therefore, the increase in cell capacity can be attributed to an enhanced Li+ flux due to the higher Li+ concentration gradient at the surface of the cathode. X-ray photoelectron spectroscopy and scanning electron microscopy results indicate that the Li-powder anode not only suppressed side reactions in the electrolyte but also promoted uniform lithium peroxide deposition on the cathode of the Li-O2 cell.
Original language | English |
---|---|
Pages (from-to) | 5286-5292 |
Number of pages | 7 |
Journal | ACS Applied Energy Materials |
Volume | 4 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2021 May 24 |
Bibliographical note
Funding Information:This work was supported by grants from the National Research Foundation of Korea (NRF) and the Korean government (MSIT) (2017M3A9E2093907 and 2020R1A2C1012838). This work was also supported by the Industry-Academia Collabo program of Ministry of SMEs and Startups (MSS, Korea) [2020(S2900965), Development of source technology for high efficiency silicon oxide anode material using metal vapor reaction].
Publisher Copyright:
©
Keywords
- concentration gradient
- exchange current density
- lithium powder
- lithium-ion flux
- lithium-metal batteries
ASJC Scopus subject areas
- Chemical Engineering (miscellaneous)
- Energy Engineering and Power Technology
- Electrochemistry
- Electrical and Electronic Engineering
- Materials Chemistry