Durability of high-energy throughput batteries is a prerequisite for electric vehicles to penetrate the market. Despite remarkable progresses in silicon anodes with high energy densities, rapid capacity fading of full cells with silicon–graphite anodes limits their use. In this work, we unveil degradation mechanisms such as Li+ crosstalk between silicon and graphite, consequent Li+ accumulation in silicon, and capacity depression of graphite due to silicon expansion. The active material properties, i.e. silicon particle size and graphite hardness, are then modified based on these results to reduce Li+ accumulation in silicon and the subsequent degradation of the active materials in the anode. Finally, the cycling performance is tailored by designing electrodes to regulate Li+ crosstalk. The resultant full cell with an areal capacity of 6 mAh cm−2 has a cycle life of >750 cycles the volumetric energy density of 800 Wh L−1 in a commercial cell format.

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Rh nanoparticles in a graphite lattice have been prepared by reduction of a RhCl 3 -graphite intercalation compound by hydrogen gas at high temperatures (I) or at room temperature by Li-diphenylide (II). In all cases, the reduction was complete. All four samples (natural graphite and HOPG) showed a full set of fcc Rh reflections by selected-area electron diffraction. This indicates a particle thickness from at least four layers. Only in the case of the samples reduced by (II) can additional very strong reflections can be observed. They seem to be due to the occurrence of 2D Rh structures with (2 × a graphite ) and (3 × a graphite ) superstructures. For a (2 × a graphite ) Rh superstructure on graphite or expanded multilayers of fcc Rh, an induced magnetic moment was theoretically predicted. Bright-field electron microscopy shows particles in the size ranges 11-106 nm (I) and 1.5-37.5 nm (II). The magnetism of Rh-Gr is related to the detail of Rh nanoparticles and nanographites, depending on the condition of reduction. Short-range magnetic order is observed in Rh nanoparticles for the sample with uncommon spacings. However, Curie-like susceptibility is observed at low temperatures for all samples. This is due to nanographites with zigzag edges. As reference substances, Rh nanoparticles were generated in bentonite and on kaolin by polyol reduction of Rh-acetate hydrate. The size range in bentonite was 2.1-60 nm; the kaolin samples showed Rh particles from 5.3-52.5 nm. Electron diffraction patterns gave no evidence of an expanded lattice in those Rh particles.

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