Unveiling the Structural Evolution of Ag1.2Mn8O16 under Coulombically Controlled (De)Lithiation
- Stony Brook Univ., Stony Brook, NY (United States)
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Stony Brook Univ., Stony Brook, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
MnO2 materials are considered promising cathode materials for rechargeable lithium, sodium, and magnesi-um batteries due to their earth abundance and environmental friendliness. One polymorph of MnO2, α-MnO2, has 2×2 tunnels (4.6 Å × 4.6 Å) in its structural framework, which provide facile diffusion pathways for guest ions. In this work, a silver ion containing α-MnO2 (Ag1.2Mn8O16) is examined as a candidate cathode material for Li based batteries. Electro-chemical stability of Ag1.2Mn8O16 is investigated through Coulombically controlled reduction under 2 or 4 molar electron equivalents (e.e.). Terminal discharge voltage remains almost constant under 2 e.e. of cycling, whereas it continuously decreases under repetitive reduction by 4 e.e. Thus, detailed structural analyses were utilized to investigate the structural evolution upon lithiation. Significant increases in lattice a (17.7 %) and atomic distances (~4.8 %) are observed when x in LixAg1.2Mn8O16 is >4. Ag metal forms at this level of lithiation concomitant with a large structural distortion to the Mn-O framework. In contrast, lattice a only expands by 2.2 % and Mn-O/Mn-Mn distances show minor changes (~1.4 %) at x <2. The structural deformation (tunnel breakage) at x >4 inhibits the recovery of the original structure, leading to poor cycle stability at high lithiation levels. This report establishes the correlation among local structure changes, amorphization processes, formation of Ag0 and long term cycle stability for this silver containing α-MnO2 type material at both low and high lithiation levels.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Mesoscale Transport Properties (m2mt); Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0012704
- OSTI ID:
- 1434772
- Report Number(s):
- BNL-203551-2018-JAAM; TRN: US1802821
- Journal Information:
- Chemistry of Materials, Vol. 30, Issue 2; ISSN 0897-4756
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Capacity Retention for (De)lithiation of Silver Containing α-MnO 2 : Impact of Structural Distortion and Transition Metal Dissolution
|
journal | January 2018 |
Review of the Stability/Capacity Trade-off in Silver Hollandite Lithium Battery Cathodes
|
journal | January 2018 |
Defect Control in the Synthesis of 2 D MoS 2 Nanosheets: Polysulfide Trapping in Composite Sulfur Cathodes for Li–S Batteries
|
journal | March 2020 |
Similar Records
Review of the Stability/Capacity Trade-off in Silver Hollandite Lithium Battery Cathodes
Silver-Containing α-MnO2 Nanorods: Electrochemistry in Na-Based Battery Systems