Porous Si/Cu6Sn5/C composite containing native oxides as anode material for lithium-ion batteries

Yawen He (1, 2) , Zhongbin Ye (1) , Mohamad Chamas (1) , Moulay Tahar Sougrati (2) , Pierre-Emmanuel Lippens (2)

1 Southwest Petroleum University
2 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

Porous Si/Cu6Sn5/C composite containing native oxides was prepared via solid state mechanical milling and wet chemical etching. This composite was used as anode material for Li-ion batteries. X-ray diffraction, electron microscopy, 119 Sn Mössbauer spectroscopy and X-ray photoelectron spectroscopy show that the composite has a pitaya-like morphology based on porous Si and embedded Cu6Sn5 nonporous microparticles with surface native oxides. Both Si and Cu6Sn5 are electrochemically active and the activation process during the first charge-discharge cycles improves the nanostructuration of the composite that helps to buffer the volume variations of the Li-Si and Li-Sn alloying reactions. The porous composite delivers a reversible and stable capacity of 900 mAh.g-1 at a galvanostatic current density of 422 mA.g-1 with a retention of 90% for 100 cycles, which is higher than porous Si (53%). The stability during cycling is explained by buffering effects, enhanced electrode conductivity and stable SEI due to the presence of native oxides and the use of FEC-containing electrolyte.

Mots clés: porous Si composite; anode; passivation

Domaines: Matériaux

Yawen He, Zhongbin Ye, Mohamad Chamas, Moulay Tahar Sougrati, Pierre-Emmanuel Lippens. Porous Si/Cu6Sn5/C composite containing native oxides as anode material for lithium-ion batteries. Journal of Materials Science: Materials in Electronics, 2022, 33, pp.235-243. ⟨10.1007/s10854-021-07288-1⟩. ⟨hal-03415279⟩