1、Lithium Battery Research for Vehicle Technology at Brookhaven National Lab. X. Q. Yang, K. W. Nam, X.J. Wang, Y.N. Zhou, H. S. Lee, O. Haas, L. Wu, and Y. ZhuBrookhaven National Lab. Upton, NY11973, USAH. Li, X. Huang and L. Chen Institute of Physics, Chinese Academy of Sciences, , ChinaTo be presen

2、ted at 2021 International Forum on Li-ion Battery Technology & Industrial Development , China, October 16-18, 2021Center for Functional Nano-materials at BNLNSLS experimental floor45678Experimental Setup at X7B (NSLS) with Image Plate Detector (IPD) and in situ cellMylar sheetBolt holesX-ray windowG

3、asketSeparator Cu currentcollectorAl currentcollectorCathode Anodein situ cell10111213141516171819Lattice parameter changes during 1st charge: half cell Spinel, Layered and Mixed Cathode Spinel Layered Discharge/charge curve and in situ XRD scans : pouch cell Mixed Cathode & Carbon Anode Cathode: Mi

4、xed LiMn2O4 + LiCo1/3Ni1/3Mn1/3O2, 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 phaseDischargeChargeSpinel Layered Lattice parameter changes durin

5、g discharge/charge: pouch cell Mixed Cathode & Carbon Anode Cathode: Mixed LiMn2O4 + LiCo1/3Ni1/3Mn1/3O2, Anode: Carbon,Voltage range: 2.5 V 4.2 V, Charge rate: C/2 (capacity = 10 mAh),Unit cell volume changes during charge: Comparison of half cell and pouch cellSpinel Layered Half cell : Mixed LiMn

6、2O4 + LiCo1/3Ni1/3Mn1/3O2 cathode + Li foil anodePouch cell : Mixed LiMn2O4 + LiCo1/3Ni1/3Mn1/3O2 cathode + Carbon anodeLattice 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 ra

7、tes : Pouch cell : Mixed Cathode & Carbon Anode Spinel Layered Summaries - I In the half cell composed of mixed cathode and Li foil anode, structural changes can be divided into three typical regions with x in the Li1-xMO mixed cathode (LiCo1/3Ni1/3Mn1/3O2 + LiMn2O4) upon first charge up to 5.2V vs.

8、 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 layered component Region III (x= 0.4 to 1.0) : Continuous structural changes of layered component only after completion of spi

9、nel component phase transition In the pouch cell composed of mixed cathode and carbon anode, the mixed cathode shows completely reversible structural changes during charge/discharge.Summaries - II In the pouch cell composed of mixed cathode and carbon anode, most of the structural changes (i.e., cap

10、acity) of pouch cell are attributed to the spinel component when operated between 2.5 4.2V. 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. When discharge rate increases from C/2

11、to 4C, spinel component in the mixed pouch cell follows well the structural changes shown at C/2 whereas layered component doesnt, indicating better high rate capability of the spinel component. The time resolved XRD technique developed at BNL is a very powerful tool for studying the structural changes of the new mixed cathode developed