In:
Journal of The Electrochemical Society, The Electrochemical Society, Vol. 170, No. 4 ( 2023-04-01), p. 040521-
Abstract:
Development of delithiation methods with cost-efficiency and highly kinetic effectivity is of great importance for the preparation of diversified intercalation materials, mechanistic study, and lithium extraction from spent lithium-ion batteries. Electrochemical delithiation in aqueous electrolytes is low-cost, straightforward, and fast, but has been plagued by incomplete delithiation. To address this issue, we propose to add oxidation reagents, usually applied in chemical delithation, to traditional aqueous delithiation electrolyte. As a demonstration, herein, a Na 2 SO 4 + Na 2 S 2 O 8 composite aqueous electrolyte is used to obtain olivine FePO 4 from the electrochemical delithiation of LiFePO 4 , and compared with the similar delithiation in Na 2 SO 4 aqueous electrolyte. The delithiation goes completion in the composite electrolyte 79% faster than that in traditional electrolyte. The resulting olivine FePO 4 exhibits integrity in terms of structure and electrochemical properties, with discharge specific capacity of 157.1 mAh g −1 at 0.1 C, constant voltage plateau of 3.37 V, and 98.8% capacity retention after 100 cycles, all comparable to the LiFePO 4 starting material. Mechanistic studies show that Na 2 S 2 O 8 promotes the electrochemical delithiation by providing acidic and chemically oxidative conditions.
Type of Medium:
Online Resource
ISSN:
0013-4651
,
1945-7111
DOI:
10.1149/1945-7111/accb0f
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2023
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