Solvation dynamics critically affect charge transport. Spectroscopic experiments and computer simulations show that these dynamics in aqueous systems occur on a picosecond timescale. In the case of organic electrolytes, however, conflicting values ranging from 1 to several 100 picoseconds have been reported. We resolve this conflict by studying mixtures of an organic polymer and a lithium salt. Lithium ions coordinate with multiple polymer chains, resulting in temporary crosslinks. Relaxation of these crosslinks, detected by quasielastic neutron scattering, are directly related to solvation dynamics. Simulations reveal a broad spectrum of relaxation times. The average timescale for solvation dynamics in both experiment and simulation is one nanosecond. We present the direct measurement of ultraslow dynamics of solvation shell break-up in an electrolyte.

溶剂化动力学严重影响电荷传输。光谱实验和计算机模拟表明，水系统中的这些动力学发生在皮秒时间尺度上。然而，在有机电解质的情况下，已经报道了从 1 到几百皮秒的相互矛盾的值。我们通过研究有机聚合物和锂盐的混合物解决了这一冲突。锂离子与多个聚合物链配位，产生临时交联。通过准弹性中子散射检测到的这些交联的松弛与溶剂化动力学直接相关。模拟揭示了广泛的弛豫时间。实验和模拟中溶剂化动力学的平均时间尺度都是一纳秒。我们提出了电解质中溶剂化壳破裂的超慢动力学的直接测量。