Embedding the high entropy alloy nanoparticles into carbon matrix toward high performance Li-ion batteries

The alloying type materials have been proposed to be served as the alternative anode for lithium ion batteries (LIBs) owing to their much higher capacity than graphite. However, those elementary alloying substances still suffer large volume expansion, resulting in much Li-irreversibility of low initial coulombic efficiency (ICE<75%) and fast capacity fading. Herein, inspired by the high entropy concept, we extend the simple elements into the high entropy alloy (HEA) system by rational designing Li-active and high conductive components. Interestingly, one kind atomic disorder HEA composed of Ge-Sn-Sb-Si-Fe-Cu-P is successfully synthesized for the first time, which is surprisingly found delivered ultra-high reversibility (e.g. ICE=91%) for LIBs, combining with suitable plateau (∼0.5 V) and large discharge capacity (1448 mAh/g) as well. Furthermore, such formed HEA nanoparticles are greatly emdedded and encapsulated into carbon matrix to form a dragon-fruit-like HEA/C composite. Benefitted from above unique structural design, the HEA/C composite exhibits superior cyclability (>1600 h operation) and excellent rate performances (787 mAh/g and 63% retention at 2000 mA/g). This successful implement of high entropy concept into alloying type anode materials may open a new avenue to developing series high entropy alloys toward advanced energy storage.