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.
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+).
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. 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.
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). Moreover, ANL-1NM3 (14-1930) CAS864079-62-9 electrolytes with a 0.8M LiBOB salt concentration are stable to 4.4 V, despite the fact that most oligoether linkages (CH2−CH2−O)n undergo oxidative decomposition above 4.0 V.
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 . 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 . The conductivity of 0.8M LiBOB in ANL-1S1M3 electrolyte is 1.29 x 10–3 S cm–1 at 25°C.
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