汽车用锂电池研究

can be divided into three typical regions with x in t源自文库e Li1-xMO mixed cathode (LiCo1/3Ni1/3Mn1/3O2 + LiMn2O4) upon first charge up to 5.2V vs. Li/Li+.
• Region I (x= 0.0 to ~ 0.1) : Structural changes of LiCo1/3Ni1/3Mn1/3O2 component only • Region II (x= 0.1 to ~ 0.4) : Dominant structural changes by spinel component over
•Lattice parameter changes during discharge at C/2 and 4C rates :
Pouch cell : Mixed Cathode & Carbon Anode
•Spinel
•Layered
•Unit cell volume changes during discharge at C/2 and 4C rates :
•Unit cell volume changes during charge: Comparison of half cell and pouch cell
•Spinel
•Layered
•Half cell : Mixed LiMn2O4 + Li[Co1/3Ni1/3Mn1/3]O2 cathode + Li foil anode •Pouch cell : Mixed LiMn2O4 + Li[Co1/3Ni1/3Mn1/3]O2 cathode + Carbon anode
Pouch cell : Mixed Cathode & Carbon Anode
•Spinel
•Layered
•Summaries - I
•◈ In the half cell composed of mixed cathode and Li foil anode, structural changes
•Summaries - II
•◈ In the pouch cell composed of mixed cathode and carbon anode, most of the
structural changes (i.e., capacity) of pouch cell are attributed to the spinel component when operated between 2.5 ~ 4.2V.
•◈ The time resolved XRD technique developed at BNL is a very powerful tool for studying the structural changes of the new mixed cathode developed by LG chemical during charge-discharge cycling, especially at the high rate.
transition
•◈ In the pouch cell composed of mixed cathode and carbon anode, the mixed
cathode shows completely reversible structural changes during charge/discharge.
•◈ When discharge rate increases from C/2 to 4C, spinel component in the mixed pouch cell follows well the structural changes shown at C/2 whereas layered component doesn’t, indicating better high rate capability of the spinel component.
汽车用锂电池研究
2020年7月18日星期六
•Center for Functional Nano-materials at BNL
•NSLS experimental floor
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•6
•7
•8
•Experimental Setup at X7B (NSLS) with Image Plate Detector (IPD) and in situ cell
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•1 6
•1 7
•1 8
•1 9
•Lattice parameter changes during 1 charge: half cell
Spinel, Layered and Mixed Cathode
•Spinel
•Layered
•Discharge/charge curve and in situ XRD scans : pouch cell Mixed Cathode & Carbon Anode
•
layered component
• Region III (x= 0.4 to ~ 1.0) : Continuous structural changes of layered component
•
only after completion of spinel component phase
•
•◈ When discharge rate increases from C/2 to 4C, kinetically induced two phase region clearly is seen in the in situ XRD, which was not observed in the in situ XRD at C/2.
•Mylar sheet •Bolt holes
•Gasket
•Separator
•X-ray window
•Al current •collector
• Cu current •collector
•Catho•de Anode
•in situ cell
•1 0
•1 1
•1 2
•1 3
•1 4
•Charge
•Discharg e
•Cathode: Mixed LiMn2O4 + Li[Co1/3Ni1/3Mn1/3]O2, Anode: Carbon, •Voltage range: 2.5 V – 4.2 V, Charge rate: C/2 (capacity = 10 mAh), •Blue & green lines: before discharge & charge, Red & purple lines: after discharge & charge, •S: Spinel phase, L: Layered phase
•Lattice parameter changes during discharge/charge: pouch cell
Mixed Cathode & Carbon Anode
•Spinel
•Layered
•Cathode: Mixed LiMn2O4 + Li[Co1/3Ni1/3Mn1/3]O2, Anode: Carbon, •Voltage range: 2.5 V – 4.2 V, Charge rate: C/2 (capacity = 10 mAh),