TY - JOUR
T1 - Revealing sodium storage mechanism in lithium titanium phosphate
T2 - Combined experimental and theoretical study
AU - Voronina, Natalia
AU - Jo, Jae Hyeon
AU - Choi, Ji Ung
AU - Konarov, Aishuak
AU - Kim, Jongsoon
AU - Myung, Seung Taek
N1 - Funding Information:
This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) , funded by the Ministry of Education, Science, and Technology of Korea ( NRF 2015M3D1A1069713 , NRF 2017R1E1A2A01079404 , NRF 2017M2A2A6A01070834 and NRF 2017K1A3A1A30084795 ).
PY - 2020/4/15
Y1 - 2020/4/15
N2 - We investigate a LiTi2(PO4)3–carbon composite (LTP-C) with a sodium superionic conductor (NASICON)-type structure as a potential electrode material for sodium storage. Operando X-ray diffraction and ex situ X-ray absorption spectroscopic analyses reveal that repetitive electrochemical reduction (discharge) and oxidation (charge) between 1.2 and 3.1 V results in a two-phase redox process associated with the Ti4+/3+ redox couple. The rearrangement of the alkali sites during discharge/charge is investigated using first-principles calculations and Rietveld refinement. Using first-principles calculations, we verify the possibility of ion exchange from Li+ to Na+ in LiTi2(PO4)3 in Na cells as well as various theoretical electrochemical properties of LiNa2Ti2(PO4)3 and Na3Ti2(PO4)3. Notably, the sodiated LTP-C exhibits a stable cycle life for over 300 cycles at 0.5C and for over 1000 cycles at 5C with capacity retention of 99% and 94%, respectively.
AB - We investigate a LiTi2(PO4)3–carbon composite (LTP-C) with a sodium superionic conductor (NASICON)-type structure as a potential electrode material for sodium storage. Operando X-ray diffraction and ex situ X-ray absorption spectroscopic analyses reveal that repetitive electrochemical reduction (discharge) and oxidation (charge) between 1.2 and 3.1 V results in a two-phase redox process associated with the Ti4+/3+ redox couple. The rearrangement of the alkali sites during discharge/charge is investigated using first-principles calculations and Rietveld refinement. Using first-principles calculations, we verify the possibility of ion exchange from Li+ to Na+ in LiTi2(PO4)3 in Na cells as well as various theoretical electrochemical properties of LiNa2Ti2(PO4)3 and Na3Ti2(PO4)3. Notably, the sodiated LTP-C exhibits a stable cycle life for over 300 cycles at 0.5C and for over 1000 cycles at 5C with capacity retention of 99% and 94%, respectively.
KW - First-principles calculations
KW - Insertion
KW - Ion exchange
KW - Lithium titanium phosphate
KW - Sodium-ion batteries
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U2 - 10.1016/j.jpowsour.2020.227976
DO - 10.1016/j.jpowsour.2020.227976
M3 - Article
AN - SCOPUS:85080888649
VL - 455
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
M1 - 227976
ER -