Calculations on electrode materials The average intercalation voltage 4.5 Experimental rate~C/200 4.0 -E(LiyX）-(x2-x1)ELi边] 3.5 LiF+bulk Fe(GGA) (x2-x10e) 3.0 2.5 LiF+bulk Fe(Expt.E.Fit) 2.0 1.5 Computed discharge potentials 0.000.501.001.502.002.503.00 Conductivity u=D 9 KgT D=“KT=BKT x in Li FeF, a b D=-品rgoP (a) b)4 MD uuonon -6 7 D 03 AD. 8 0.5 101.5 2.0 0.51.01.52.02.53.03.5 1000/T(1/K) 1000/T(1/K)
The average intercalation voltage Conductivity Calculations on electrode materials 𝑫 = 𝐥𝐢𝐦 𝒕→∞ 𝟏 𝟐𝒅𝒕 𝒓 𝒕 − 𝒓 𝟎 𝟐
Calculations on electrode materials E=0.50eV 1.01 E=0.88eV Diffusion and its barriers Site 2 Site 3 △E=0.02eV 0.0 Site 1 △E=0.49eV Higher中/ Nominal oxidation potential Lower u “ 中-5V/: Overpotential 4=-5eV Cathode Low Hu Oxidation potential Interphase Structure and Electrochemical stability of Intrinsic Extended Electrochemica Electrochemical Window Electrode/electrolyte interfaces Window Solid Inter electrolyte Reduction potential Anode 中=0V/ High u phase =0eV
Diffusion and its barriers Calculations on electrode materials Structure and Electrochemical stability of Electrode/electrolyte interfaces
PHYSICAL REVIEW B 82.075122 (2010) Methodologies Hybrid density functional calculations of redox potentials and formation energies of transition metal compounds V.L.Chevrier.S.P.Ong.R.Armiento.M.K.Y.Chan.and G.Ceder HSE06 is as successful as GGA+U in predicting Jahn-Teller Depurtment of Muterials Science and Engineering.Massachusetts Institute of Technology.Cambridge,02139.USA (Received 12 February 2010:revised manuscript received 18 July 2010:published 12 August 2010) distortions,magnetic moments,and charge localization. TABLE I.Values of the (parameters in electron volt,adapted (a)GGA+U (b)HSE06 from Ref.3. HSE06 consistently predicts more accurate geometries than Olivine Layered Spinel both GGA and GGA+U Mn 4.5 48 Fe 4.3 HSE06 and GGA+U with a linear response U yield similar Co 5.7 5.1 Ni 61 6.4 accuracies for Li intercalation potentials. Isosurfaces of the change in charge density upon lithiation of Relative error of the optimized volumes compared NiPO4 to LiNiPO4 to experiment for the lithiated phases Average Li intercalation potentials vs.Li/Li,in volts 15 GGA● GGA GGA+U HSE06 Expt. 0.6 GGA-⊙ GGA+U LiCoO: 3.38 3.85 4.51 4.1 GGA+U△ 10 HSE06 LiNiO2 3.08 3.92 4.14 3.9 0.2 HSE06日 LiTiS, 1.91 (1.91) 206 21 0 回 LixTixO 1.05 (1.05) 1.19 1.3 LiMn2O 3.37 4.04 425 4.1 0.2 LiMnPO 2.99 4.01 3.87 4.1 04 LiFePO 2.84 3.47 3.33 3.5 LiCoPO 3.62 4.63 4.57 4.8 0,6 LiNiPO 4.15 5.00 541 53 0.8 Mean 2.93 3.54 3.70 3.69 -1 MAE 0.76 0.15 0.19 10 -1.2 Delithiation to LiTiO. L甜 LiNiPO is unstable upon delithiation,leading to a larger error in average intercalation potential. Mean absolute error
Methodologies ✓ HSE06 is as successful as GGA+U in predicting Jahn-Teller distortions, magnetic moments, and charge localization. ✓ HSE06 consistently predicts more accurate geometries than both GGA and GGA+U. ✓ HSE06 and GGA+U with a linear response U yield similar accuracies for Li intercalation potentials. Isosurfaces of the change in charge density upon lithiation of NiPO4 to LiNiPO4 Average Li intercalation potentials vs. Li/Li+ in volts Relative error of the optimized volumes compared to experiment for the lithiated phases
ZnCo2O is a promising candidate as the anode material of LIBs,and one can expect a total capacity corresponding to The Structural 7.0-8.33 mol of recyclable Li per mole of ZnCo2. Stability of Spinel However,the high capacity drops extensively in discharge- ZnCo2O4 as an charge cycles in practical experiments. Electrode Material ZnCo204+8Lit 8e-Zn+2Co +4Li2O (1) for Lithium-ion Zn+Lit+e←→LiZn (2) Batteries Zn+Li20←→ZnO+2Lit+2e (3) 2Co+2Li20←→2Co0+4Lit+4e (4) 2Co0+2/3Li20←→2/3Co3O4+4/3Lit+4/3e (5) SCIENTIFIC REPORTS|6:36717|DOI:10.1038/srep36717
The Structural Stability of Spinel ZnCo2O4 as an Electrode Material for Lithium-ion Batteries ZnCo2O4 is a promising candidate as the anode material of LIBs, and one can expect a total capacity corresponding to 7.0 - 8.33 mol of recyclable Li per mole of ZnCo2O4 . However, the high capacity drops extensively in dischargecharge cycles in practical experiments
Structural and Electronic Properties 7r尚f bie品spinel 0 (b)Tetragonal spinel Relative Space group Magnetism energy (eV) Lattice constants(A) Fd3m(C) NFM 0 a=b=c=8.164(8.10) ⊙p 141/amd (T) FM +2.30 a=5.893.b=5.920, c=8.592 texs! ZnCoO:Nonmagnetic cubic spinel b M=o 12 (a (b) Total DOS VBM:Co-3d and O-2p orbitals; 0 Zn Co Eg=2.22 eV CBM:Co-3d states; 8 VBM shows a flat dispersion,leading to 6 heavy holes with large effective masses and a poor p-type conductivity. -2 elecmic十ekwe Energy (eV)
Structural and Electronic Properties ZnCo2O4 : Nonmagnetic cubic spinel VBM: Co-3d and O-2p orbitals; CBM: Co-3d states; VBM shows a flat dispersion, leading to heavy holes with large effective masses and a poor p-type conductivity