Lithium‐ion battery cells with high‐energy density and good fast charging properties are subject of current research. One approach to achieve high‐energy densities is the use of higher mass loadings. The challenges of these so called “thick” electrodes are transport limitations: lithium ions cannot reach all layers of the electrode, which results in a drop of performance. Possible concepts to overcome these limitations are the use of different active materials (silicon oxide, graphite, and hard carbon (HC)), and a two‐layer coating of the anode to create a defined pore network, which reduces the ionic resistance and ensure better fast charging capability even at higher mass loadings (8 mAh cm−2). It could be demonstrated that by using a two‐layered anode with HC in the upper layer, the electrical conductivity could be increased by a factor of 10 compared to the reference anode. Furthermore, the interporous HC leads to a capacity retention increase up to 20% with no loss of capacity at moderate C‐rates and a low electrode density. This can be explained by the low tortuosity that results in additional conductive paths for the ions through the coating, reduces the ionic resistance, and ultimately enables faster lithiation of the anode.

Lithium‐ion batteries ensuring high energy densities are the focus of ongoing research. The main challenge is the fast charging capability, which is restricted by transport limitations of the lithium‐ions. For this reason, graphite (Gr) and hard carbon (HC) blend anodes at different calendering degrees and, thus, electrode densities are investigated in terms of their structural features as well as their electrochemical performance. The motivation of blend anodes is the combination of the advantageous properties of these materials. Due to the different microstructures of Gr and HC, major differences in the lithiation process can be found. While the turbostratic structure of HC enables fast charging, its large specific surface area is associated with a low initial Coulombic efficiency and, thus, a loss of capacity. Consequently, the combination with Gr in blends is reasonable. While the lithium‐ion diffusion is enhanced using HC, the availability of the interporous structure of HC is highly dependent on the electrode density. In addition to an increase in adhesion strength and reduction in electrical resistance, a reduction in tortuosity and lithium plating can be demonstrated. Furthermore, a higher capacity retention in the charge rate test (up to 3C) at low coating densities was found for the blends.

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