POSS-PEO（n = 4）（8）与高分子量聚环氧乙烷的共混物作为锂电池的固体聚合物电解质。

Zhang Hanjun, Kulkarni Sunil, Wunder Stephanie L

Department of Chemistry 016-11, Temple University, Philadelphia, Pennsylvania 19122, USA.

J Phys Chem B. 2007 Apr 12;111(14):3583-90. doi: 10.1021/jp064585g. Epub 2007 Mar 21.

Solid polymer electrolyte blends were prepared with POSS-PEO(n=4)8 (3K), poly(ethylene oxide) (PEO(600K)), and LiClO4 at different salt concentrations (O/Li = 8/1, 12/1, and 16/1). POSS-PEO(n=4)8/LiClO4 is amorphous at all O/Li investigated, whereas PEO(600K) is amorphous only for O/Li = 8/1 and semicrystalline for O/Li = 12/1 and 16/1. The tendency of PEO(600K) to crystallize limited the amount of POSS-PEO(n=4)(8) that could be incorporated into the blends, so that the greatest incorporation of POSS-PEO(n=4)(8) occurred for O/Li = 8/1. Blends of POSS-PEO(n=4)(8)/PEO(600K)/LiClO4 (O/Li = 8/1 and 12/1) microphase separated into two amorphous phases, a low T(g) phase of composition 85% POSS-PEO(n=4)(8)/15% PEO(600K) and a high T(g) phase of composition 29% POSS-PEO(n=4)(8)/71% PEO(600K). For O/Li = 16/1, the blends contained crystalline (pure PEO(600K)), and two amorphous phases, one rich in POSS-PEO(n=4)(8) and one rich in PEO(600K). Microphase, rather than macrophase separation was believed to occur as a result of Li(+)/ether oxygen cross-link sites. The conductivity of the blends depended on their composition. As expected, crystallinity decreased the conductivity of the blends. For the amorphous blends, when the low T(g) (80/20) phase was the continuous phase, the conductivity was intermediate between that of pure PEO(600K) and POSS-PEO(n=4)(8). When the high T(g) (70/30, 50/50, 30/70, and 20/80) phase was the continuous phase, the conductivity of the blend and PEO(600K) were identical, and lower than that for the POSS-PEO(n=4)(8) over the whole temperature range (10-90 degrees C). This suggests that the motions of the POSS-PEO(n=4)(8) were slowed down by the dynamics of the long chain PEO(600K) and that the minor, low Tg phase was not interconnected and thus did not contribute to enhanced conductivity. At temperatures above T(m) of PEO(600K), addition of the POSS-PEO(n=4)(8) did not result in conductivity improvement. The highest RT conductivity, 8 x 10(-6) S/cm, was obtained for a 60% POSS-PEO(n=4)(8)/40% PEO(600K)/LiClO4 (O/Li = 12/1) blend.

采用聚倍半硅氧烷 - 聚环氧乙烷（POSS-PEO(n=4)8）（3K）、聚环氧乙烷（PEO(600K)）和高氯酸锂（LiClO4）制备了不同盐浓度（氧/锂 = 8/1、12/1和16/1）的固体聚合物电解质共混物。在所有研究的氧/锂比例下，POSS-PEO(n=4)8/LiClO4均为非晶态，而PEO(600K)仅在氧/锂 = 8/1时为非晶态，在氧/锂 = 12/1和16/1时为半晶态。PEO(600K)的结晶倾向限制了可掺入共混物中的POSS-PEO(n=4)(8)的量，因此在氧/锂 = 8/1时，POSS-PEO(n=4)(8)的掺入量最大。POSS-PEO(n=4)(8)/PEO(600K)/LiClO4（氧/锂 = 8/1和12/1）的共混物微相分离为两个非晶相，一个是低玻璃化转变温度（T(g)）相，组成为85% POSS-PEO(n=4)(8)/15% PEO(600K)，另一个是高T(g)相，组成为29% POSS-PEO(n=4)(8)/71% PEO(600K)。对于氧/锂 = 16/1，共混物包含结晶态（纯PEO(600K)）以及两个非晶相，一个富含POSS-PEO(n=4)(8)，另一个富含PEO(600K)。由于锂离子/醚氧交联位点，认为发生的是微相分离而非宏观相分离。共混物的电导率取决于其组成。正如预期的那样，结晶度降低了共混物的电导率。对于非晶态共混物，当低T(g)（80/20）相为连续相时，电导率介于纯PEO(600K)和POSS-PEO(n=4)(8)之间。当高T(g)（70/30、50/50、30/70和20/80）相为连续相时，共混物和PEO(600K)的电导率相同，且在整个温度范围（10 - 90摄氏度）内低于POSS-PEO(n=4)(8)的电导率。这表明长链PEO(600K)的动力学减缓了POSS-PEO(n=4)(8)的运动，并且次要的低玻璃化转变温度相未相互连接，因此对提高电导率没有贡献。在高于PEO(600K)熔点（T(m)）的温度下，添加POSS-PEO(n=4)(8)并未导致电导率提高。对于60% POSS-PEO(n=4)(8)/40% PEO(600K)/LiClO4（氧/锂 = 12/1）的共混物，获得了最高的室温电导率，为8×10⁻⁶ S/cm。