The rheological behavior of anode slurries for lithium-ion batteries, containing both natural and synthetic graphite as active material, was investigated with a focus on the different graphite morphologies. When the solid content is low, slurries containing synthetic graphite with a discotic shape display greater viscoelasticity than slurries containing natural graphite with a relatively more spherical shape. This result is attributed to the anisotropic geometry and interparticle force of the synthetic graphite. When the solid content is high, slurries comprising synthetic graphite exhibit lower viscoelasticity than slurries containing natural graphite. Tap density and sedimentation experiments reveal that, due to discotic shape and surface-to-surface attraction, synthetic graphite aggregates to a more densely packed aggregate than natural graphite. Consequently, in conditions of high solid contents where graphite has a greater chance of formation of densely packed aggregates, it is expected that synthetic graphite will have a more compact aggregate structure and a smaller effective volume. The smaller viscoelasticity of synthetic graphite slurries at more concentrated regions, where the effective volume of clusters plays more important role than in dilute regions, is attributed to the surface-to-surface aggregated structure of the synthetic graphite and the resulting small effective volume. Although the effective volume fraction of the graphite aggregates is reduced, slurries made of synthetic graphite demonstrate significant strain stiffening. Our findings suggest that the strain stiffening observed may originate from the anisotropic morphology, which possesses a significant surface area and is accompanied by jamming and high friction.

研究了含有天然石墨和合成石墨作为活性材料的锂离子电池阳极浆料的流变行为，重点关注不同的石墨形态。当固体含量低时，含有盘状形状的合成石墨的浆料比含有相对更球形的天然石墨的浆料表现出更大的粘弹性。这一结果归因于人造石墨的各向异性几何形状和颗粒间力。当固体含量高时，包含合成石墨的浆料表现出比包含天然石墨的浆料更低的粘弹性。振实密度和沉降实验表明，由于盘状形状和表面间的吸引力，人造石墨聚集成比天然石墨更致密的聚集体。因此，在高固含量条件下，石墨更有可能形成致密聚集体，预计人造石墨将具有更致密的聚集体结构和更小的有效体积。合成石墨浆料在较集中的区域具有较小的粘弹性，其中团簇的有效体积比在稀薄区域中起着更重要的作用，这归因于人造石墨的表面到表面的聚集结构以及由此产生的较小的有效体积。尽管石墨聚集体的有效体积分数降低，但由合成石墨制成的浆料表现出显着的应变硬化。我们的研究结果表明，观察到的应变硬化可能源于各向异性形态，该形态具有很大的表面积，并伴有堵塞和高摩擦。