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  • Thermal Stability Comparison of LiFePO 4 /Graphite and LiMn 0.6 Fe 0.4 PO 4 /Graphite Pouch Cells using Accelerating Rate Calorimetry
Title: Thermal Stability Comparison of LiFePO 4 /Graphite and LiMn 0.6 Fe 0.4 PO 4 /Graphite Pouch Cells using Accelerating Rate Calorimetry
LiMn0.6Fe0.4PO4has attracted attention as a promising, high-energy, and cost-effective alternative to LiFePO4(LFP) for lithium-ion batteries. However, its thermal stability, especially at full cell level, remains less understood compared to LFP. This study compares the cycling performance and thermal stability of LiMn0.6Fe0.4PO4/graphite and LFP/graphite pouch cells using a consistent electrolyte formulation: 1.2 m lithium bis(fluorosulfonyl)imide (LiFSI) in ethylene carbonate (EC):ethyl methyl carbonate (EMC):dimethyl carbonate (DMC) (25:5:70 by volume) with 2 wt% vinylene carbonate (VC). Thermal stability was evaluated with two ∼250 mAh pouch cells through accelerating rate calorimetry at elevated temperatures. After roughly 275 cycles at C/3 and 40 °C, the LFP/graphite cells retained 91% of their initial capacity, while LMFP/graphite cells retained 89%, indicating slightly better electrochemical stability for LFP cells. Exothermic reactions in LMFP cells initiated around 125 °C, compared to 140 °C for LFP, implying higher thermal vulnerability. Despite this, both cell types exhibited similar self-heating rates below 0.1 °C min−1, demonstrating strong safety performance. Overall, although LMFP offers a higher voltage window, its thermal stability and cycling performance still slightly lag behind LFP.  more » « less
Award ID(s):
2301719
PAR ID:
10662357
Author(s) / Creator(s):
; ;
Publisher / Repository:
IOP Publishing Limited
Date Published:
Journal Name:
Journal of The Electrochemical Society
Volume:
172
Issue:
9
ISSN:
0013-4651
Page Range / eLocation ID:
090532
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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