Thermal relaxation of lithium dendrites
Physical Chemistry Chemical Physics, cilt.17, sa.12, ss.8000-8005, 2015 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 17 Sayı: 12
- Basım Tarihi: 2015
- Doi Numarası: 10.1039/c4cp05786d
- Dergi Adı: Physical Chemistry Chemical Physics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.8000-8005
- Boğaziçi Üniversitesi Adresli: Hayır
Özet
The average lengths of lithium dendrites produced by charging symmetric Li0 batteries at various temperatures are matched by Monte Carlo computations dealing both with Li+ transport in the electrolyte and thermal relaxation of Li0 electrodeposits. We found that experimental (T) variations cannot be solely accounted by the temperature dependence of Li+ mobility in the solvent but require the involvement of competitive Li-atom transport from metastable dendrite tips to smoother domains over ΔE‡R ∼ 20 kJ mol-1 barriers. A transition state theory analysis of Li-atom diffusion in solids yields a negative entropy of activation for the relaxation process: ΔS‡R ≈ -46 J mol-1 K-1 that is consistent with the transformation of amorphous into crystalline Li0 electrodeposits. Significantly, our ΔE‡R ∼ 20 kJ mol-1 value compares favorably with the activation barriers recently derived from DFT calculations for self-diffusion on Li0(001) and (111) crystal surfaces. Our findings suggest a key role for the mobility of interfacial Li-atoms in determining the morphology of dendrites at temperatures above the onset of surface reconstruction: TSR ≈ 0.65 TMB (TMB = 453 K: the melting point of bulk Li0).