Document Type : Original Reaearch Article

Author

Ceramic Research Center , Materials and Energy research Center , Karaj, Iran.

Abstract

Cathode material of Li-ion batteries is responsible for performances and behaviours of these high energy storage devices. In this study, olivine, LiFePO4 (LFP), with Pnma space group (orthorhombic) is evaluated by density functional theory (DFT) using Wien2k program. Calculations were performed by different methods, i. e. LSDA, PBE-GGA, LSDA+U, GGA+U, modified Becke-Johnson (mBJ) and PBE-Fock-a (a Hybrid Functionals method, named HF). Assessments showed structural stability after extraction of one Li per formula. The relaxed structure using LSDA (GGA) calculations was underestimated (overestimated) regarding experimental structure data.  According to the calculations, the most shrinkage after Li extraction is occurred in ab plane, which could cause uniform domino-cascade Li extraction in c direction. This phenomenon would lead to constant voltage in charging/discharging. Considering experimental reaction voltage value is 3.2 V, the closest theoretical calculated voltage values belonged to GGA+U, GGA and mBJ methods. According to calculated density of states (DOS) diagrams, lithiated structure (LiFePO4) is N-type semiconductor and delithiated structure (FePO4) is P-type semiconductor. Inversely-biased-diode phenomenon turns this material as low rate capable in comparison by the oxide cathode materials. However, based on the DOS configurations, its rate capability is better than many of polyanion cathodes. Extraction of Li (turning Fe ionic state from II to III) leads to conductivity enhancement. The empty 3d-Fe orbitals are responsible for this phenomenon.

Keywords

1.      Scrosati, B. Battery technology-challenge of portable power. Nature, (1995), 373 (6515), 557-558.
2.      Gong, Z. & Yang, Y. Recent advances in the research of polyanion-type cathode materials for Li-ion batteries. Energy & Environmental Science, (2011), 4 (9), 3223-3242.
3.      Xu, B., Qian, D., Wang, Z. & Meng, Y. S. Recent progress in cathode materials research for advanced lithium ion batteries. Materials Science and Engineering: R: Reports, (2012), 73 (5), 51-65.
4.      Kim, J. & Manthiram, A. A manganese oxyiodide cathode for rechargeable lithium batteries. Nature, (1997), 390 (6657), 265-267.
5.      Sun, Y.-K. et al. High-energy cathode material for long-life and safe lithium batteries. Nature materials, (2009), 8 (4), 320-324.
6.      Kang, B. & Ceder, G. Battery materials for ultrafast charging and discharging. Nature, (2009), 458 (7235), 190-193.
7.       کزازی, م., واعظی, م. ر. & زاده, ا. ک. ساخت، مشخصه یابی و سیکل پذیری ماده کاتدی سولفور- پلی پیرول جهت کاربرد در باتری-های ثانویه لیتیمی. مجله مواد و فن آوری های پیشرفته, (1392), 2 (3), 79-85.
8.      Barpanda, P. et al. A 3.90 V iron-based fluorosulphate material for lithium-ion batteries crystallizing in the triplite structure. Nature materials, (2011), 10 (10), 772-779.
9.      Tarascon, J.-M. & Armand, M. Issues and challenges facing rechargeable lithium batteries. Nature, (2001), 414 (6861), 359-367.
10.    Fergus, J. W. Recent developments in cathode materials for lithium ion batteries. Journal of Power Sources, (2010), 195 (4), 939-954.
11.    Balandeh, M. & Asgari, S. Synthesis and characterization of LiNiO 2 nanopowder with various chelating agents. Journal of Nanomaterials, (2010), 2010, 35.
12.    Soltanmohammad, S. & Asgari, S. Characterization of LiCoO 2 nanopowders produced by sol-gel processing. Journal of Nanomaterials, (2010), 2010, 55.
13.    Kalantarian, M. M. et al. Electrochemical characterization of low-cost lithium-iron orthosilicate samples as cathode materials of lithium-ion battery. Journal of Academic and Applied Studies, (2017).
14.    Delmas, C., Maccario, M., Croguennec, L., Le Cras, F. & Weill, F. Lithium deintercalation in LiFePO4 nanoparticles via a domino-cascade model. Nature materials, (2008), 7 (8), 665-671.
15.    Recham, N. et al. A 3.6 V lithium-based fluorosulphate insertion positive electrode for lithium-ion batteries. Nature materials, (2009), 9 (1), 68-74.
16.    Nishimura, S.-i. et al. Experimental visualization of lithium diffusion in LixFePO4. Nature materials, (2008), 7 (9), 707-711.
17.    Kalantarian, M. M., Asgari, S. & Mustarelli, P. A theoretical approach to evaluate the rate capability of Li-ion battery cathode materials. Journal of Materials Chemistry A, (2014), 2 (1), 107-115.
18.    Kalantarian, M. et al. Understanding non-ideal voltage behaviour of cathodes for lithium-ion batteries. Journal of Materials Chemistry A, (2014), 2 (45), 19451-19460.
19.     صالحی, ح. ا. ساختار نوارهای انرژی در بلور آلفا آلومینا با استفاده از اصول اولیه. مجله مواد و فن آوری های پیشرفته, (1388), 2 (2), 145-150.
20.     صالحی, ح. ا. خواص اپتیکی بلور PbTiO3 در فاز مکعبی. مجله موادو فن­آوری های پیشرفته, (1389), 2 (3), 193-199.
21.    Kalantarian, M. M., Asgari, S., Capsoni, D. & Mustarelli, P. An ab initio investigation of Li 2 M 0.5 N 0.5 SiO 4 (M, N= Mn, Fe, Co Ni) as Li-ion battery cathode materials. Physical Chemistry Chemical Physics, (2013), 15, 8035-8041.
22.    Kalantarian, M. M., Asgari, S. & Mustarelli, P. Theoretical investigation of Li2MnSiO4 as a cathode material for Li-ion batteries: a DFT study. Journal of Materials Chemistry A, (2013), 1 (8), 2847-2855.
23.    Padhi, A. K., Nanjundaswamy, K. & Goodenough, J. B. d. Phospho‐olivines as Positive‐Electrode Materials for Rechargeable Lithium Batteries. Journal of the Electrochemical Society, (1997), 144 (4), 1188-1194.
24.    Megaw, H. D. Crystal structures.  (Saunders Philadelphia, 1973).
25.    Hohenberg, P. & Kohn, W. Inhomogeneous electron gas. Physical review, (1964), 136 (3B), B864.
26.    Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Physical review letters, (1996), 77 (18), 3865.
27.    Arroyo-de Dompablo, M., Armand, M., Tarascon, J. & Amador, U. On-demand design of polyoxianionic cathode materials based on electronegativity correlations: An exploration of the Li2MSiO4 system (M= Fe, Mn, Co, Ni). Electrochemistry Communications, (2006), 8 (8), 1292-1298.
28.    Saracibar, A., Van der Ven, A. & Arroyo-de Dompablo, M. Crystal structure, energetics, and electrochemistry of Li2FeSiO4 polymorphs from first principles calculations. Chemistry of Materials, (2012), 24 (3), 495-503.
29.    Jiang, X. & Guo, G. Electronic structure, magnetism, and optical properties of Fe_ {2} SiO_ {4} fayalite at ambient and high pressures: A GGA+ U study. Physical Review B, (2004), 69 (15), 155108.
30.    Zhou, F., Cococcioni, M., Kang, K. & Ceder, G. The Li intercalation potential of LiMPO< sub> 4 and LiMSiO< sub> 4 olivines with M= Fe, Mn, Co, Ni. Electrochemistry communications, (2004), 6 (11), 1144-1148.
31.    Kalantarian, M. M. & Asgari, S. Theoretical assessment of structural stability, electrochemical properties and the first cycle transition of Li2FeSiO4 as a cathode material. Journal of Academic and Applied Studies, (2017).
32.    Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Physical Review B, (1976), 13 (12), 5188-5192.
33.    Tran, F. & Blaha, P. Accurate band gaps of semiconductors and insulators with a semilocal exchange-correlation potential. Physical review letters, (2009), 102 (22), 226401.
34. کلانتریان, م. م. & عسگری, س. بررسی نظری جامع پلی­مورف­های مختلف Li2FeSiO4 به عنوان کاتد باتری لیتیم-یون با استفاده از نظریه تابعی چگالی. (1396).