Nanostructured micrometer-sized Al-Si particles are synthesized via a facile selective etching process of Al-Si alloy powder. Subsequent thin Al2O3 layers are introduced on the Si foam surface via a selective thermal wet oxidation process of etched Al-Si particles. The resulting Si/Al2O3 foam anodes exhibit outstanding cycling stability (a capacity retention of 78% after 300 cycles at the C/5 rate) and excellent rate capability.

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Nanostructuring has significantly contributed to alleviating the huge volume expansion problem of the Ge anodes. However, the practical use of nanostructured Ge anodes has been hindered due to several problems including a low tap density, poor scalability, and severe side reactions. Therefore, micrometer‐sized Ge is desirable for practical use of Ge‐based anode materials. Here, micronized Ge3N4 with a high tap density of 1.1 mg cm−2 has been successfully developed via a scalable wet oxidation and a subsequent nitridation process of commercially available micrometer‐sized Ge as the starting material. The micronized Ge3N4 shows much‐suppressed volume expansion compared to micrometer‐sized Ge. After the carbon coating process, a thin carbon layer (≈3 nm) is uniformly coated on the micronized Ge3N4, which significantly improves electrical conductivity. As a result, micronized Ge3N4@C shows high reversible capacity of 924 mAh g−1 (2.1 mAh cm−2) with high mass loading of 3.5 mg cm−2 and retains 91% of initial capacity after 300 cycles at a rate of 0.5 C. Additionally, the effectiveness of Ge3N4@C as practical anodes is comprehensively demonstrated for the full cell, showing stable cycle retention and especially excellent rate capability, retaining 47% of its initial capacity at 0.2 C for 12 min discharge/charge condition.

Multifunctional agarose acts as an effective binder for Si anodes and LiMn2O4cathodes and also serves as a good carbon source to obtain hard carbon.

We demonstrate a facile method for synthesizing silicon particles with a double coating layer consisting of aluminum trifluoride and amorphous carbon to use as an anode material for high-performance lithium-ion batteries at elevated temperatures.