Improving the life of Lithium Ion Batteries

Improving the life of Lithium Ion Batteries

Electrochemically and thermally stable polysiloxane electrolytes improve the long-time operation of lithium ion batteries
A team from Argonne National Laboratory developed silicon-based electrolytes that have emerged as primary candidates for the development of lithium-ion battery technologies. Compared to the standard carbonate based electrolytes, silicon-based electrolytes are thermally and chemically stable, less flammable, and environmental friendly.[1]
Electrolytic blend, which normally includes a lithium metal salt, an t and a redox shuttle, is one of the most economic and effective methods for the improvement of Li-ion battery performance. [2, 3] There are many types of electrolyte solvents, which are mainly characterized by conductivity, polarity (in order to dissolve the lithium salt), and thermal/ electrochemical stability with a wide potential range (0−5.0 V vs Li/Li+).[2]
ANL- 1NM2 (14-1930) CAS 864079-62-9 having a high conductivity of 1.2 x 10–3 S cm–1 at 25°C (doped with 1.0 M LiTFSI) has better electrochemical stability than its germanium and carbon analogues.[4] However, short ethylene oxide chained silane restricts the choice of lithium salts. The best soluble lithium salt in ANL- 1NM2 is LiTFSI which can be dissolved up to 1.2 M.[4]
ANL-1NM3 (14-1930) CAS864079-62-9 attracts attention due to its high conductivity (0.8M LiBOB doped electrolyte: 1.18 x 10–3 S cm–1 at 25°C or 1.0 M LiTFSI doped electrolyte: 1.0 x 10–3 S cm–1 at 25°C) and low viscosity (h = 1.4 cP at 25°C).[5] Moreover, ANL-1NM3 (14-1930) CAS864079-62-9 electrolytes with a 0.8M LiBOB salt concentration are stable to 4.4 V[6], despite the fact that most oligoether linkages (CH2−CH2−O)n undergo oxidative decomposition above 4.0 V.[2]
ANL-2SM3 (14-1943) 855996-83-7 also exhibits high electrochemical stability, high thermal stability, and low viscosity (h = 3.8 cP at 25°C). Disiloxane electrolytes doped with 0.8M LiBOB are stable to 4.7 V [7]. Compared to most of the siloxanes, ANL-2SM3 electrolyte solvent can dissolve more lithium salts such as LiBOB, LiPF6 (03-0325) CAS 21324-40-3 , LiBF4 (03-0325), CAS21324-40-3 and LiTFSI.
ANL-1S1M3 (14-1946) CAS864079-63-0 electrolyte solvent has fewer limitations towards the solvation of Li+ and can dissociate LiBOB, LiPF6 (03-0325) CAS21324-40-3 , and LiTFSI. ANL-1S1M3 is non-hydrolyzable and less flammable than alkoxysilane counterparts [8]. The conductivity of 0.8M LiBOB in ANL-1S1M3 electrolyte is 1.29 x 10–3 S cm–1 at 25°C.
References:
1. S. S. Zhang, J. Power Sources, 2006, 22, 1379.
2. K. Xu, Chem. Rev., 2014, 114, 11503.
3. S. S. Zhang, J. Power Sources, 2006, 22, 1379.
4. L. Zhang et al. J. Mater. Chem., 2008, 18, 3713.
5. Z. Chen et al. J. Phys. Chem. C, 2008, 112, 2210.
6. K. Amine et al., Electrochem. Commun. 8 (2006) 429.
7. Z. Zang et al, J. Power Sources, 2010, 195, 6062.
8. L. Zhang et al, J. Mater. Chem., 2010,

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