标题： 通过“流动切换”控制石墨/炭黑悬浮液的流电特性 显示英文标题

标题： Controlling the rheo-electric properties of graphite/carbon black suspensions by 'flow-switching'

摘要： 操纵胶体炭黑凝胶的流变和电气特性，使它们在能源应用的复合材料中具有吸引力，例如电池和燃料电池，在这些应用中，它们能够导电并防止“颗粒”活性组分的沉降。 虽然通常认为颗粒填料对复合材料的性能具有简单的加性效应，但一些复合材料可能会意外地表现出固态和液态之间的独特流变双稳态。 在这里，我们报告了非布朗石墨和油中胶体炭黑悬浮液中的这种双稳态，这是一个用于模拟能源应用复合悬浮液的模型系统。 低于临界应力的稳定剪切会引发一种持久的机械弱且导电性差的状态，必须使用高应力剪切来“恢复”为一种更强、高导电性的状态。 我们的发现突显了二元颗粒/凝胶复合悬浮液的高度可调性质，并为优化锂离子电池浆料的混合和加工条件提供了新的可能性。 显示英文摘要

摘要： The ability to manipulate rheological and electrical properties of colloidal carbon black gels makes them attractive in composites for energy applications such as batteries and fuel cells, where they conduct electricity and prevent sedimentation of `granular' active components. While it is commonly assumed that granular fillers have a simple additive effect on the composite properties, new phenomena can emerge unexpectedly, with some composites exhibiting a unique rheological bi-stability between solid-like and liquid-like states. Here we report such bi-stability in suspensions of non-Brownian graphite and colloidal carbon black in oil, a model system to mimic composite suspensions for energy applications. Steady shear below a critical stress elicits a transition to a persistent mechanically weak and poorly conducting state, which must be `rejuvenated' using high-stress shear to recover a stronger, high-conductivity state. Our findings highlight the highly tunable nature of binary granular/gel composite suspensions, and present new possibilities for optimizing mixing and processing conditions for Li-ion battery slurries.