Nanoparticle shapes of LiMnPO4, Li+ diffusion orientation and diffusion coefficients for high volumetric energy Li+ ion cathodes

JOURNAL OF POWER SOURCES

卷:342

Article

Kwon, Nam Hee¹  Yin, Hui¹  Vavrova, Tatiana¹  Lim, Jonathan H-W.²  Steiner, Ullrich³  Grobety, Bernard⁴  Fromm, Katharina M.¹ 

[1] Univ Fribourg, Dept Chem, Chemin Musee 9, CH-1700 Fribourg, Switzerland

[2] Univ Cambridge, Cavendish Lab, Dept Phys, JJ Thomson Ave, Cambridge CB3 OHE, England

[3] Adolphe Merkle Inst, Soft Matter Phys Grp, Chemin Verdiers 4, CH-1700 Fribourg, Switzerland

[4] Univ Fribourg, Dept Geosci, Chemin Musee 6, CH-1700 Fribourg, Switzerland

关键词: Nano-LiMnPO4;    Particle shape;    Li+ diffusion orientation;    Tap density;    Volumetric energy density;   

DOI  :  10.1016/j.jpowsour.2016.11.111

来源: Elsevier

【 摘 要 】

Nanoparticles of LiMnPO4 were fabricated in rod, elongated as well as cubic shapes. The 1D Li+ preferred diffusion direction for each shape was determined via electron diffraction spot patterns. The shape of nano-LiMnPO4 varied the diffusion coefficient of Li+ because the Li+ diffusion direction and the path length were different. The particles with the shortest dimension along the b-axis provided the highest diffusion coefficient, resulting in the highest gravimetric capacity of 135,100 and 60 mAh g(-1) at 0.05C, 1C and 10C, respectively. Using ball-milling, a higher loading of nano-LiMnPO4 in the electrode was achieved, increasing the volumetric capacity to 263 mAh cm(-3), which is ca. 3.5 times higher than the one obtained by hand-mixing of electrode materials. Thus, the electrochemical performance is governed by both the diffusion coefficient of Li+ which is dependent on the shape of LiMnPO4 nanoparticles and the secondary composite structure, (C) 2016 Elsevier B.V. All rights reserved.

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