LAUSR

Abstract Although Al–Si alloy with low content of Si has often been used to synthesis anode materials mainly due to the high porosity of the obtained Si powders, it still suffers many problems, such as low Si powder yield and a large amount of acid consumption. In this research, the problem that the low porosity of Si powder synthesized by Al–Si alloy with a high content of Si (Al-70 wt% Si alloy ingot) is solved by simply changing the sequence of the acid etching and ball-milling of the Al–Si alloy. As a result, with the protection of the Al matrix during the ball-milling process, the obtained porous Si powder (Si70) has a high porosity. In addition, a low-priced but excellent cationic surfactant, Poly (propylene glycol) bis (2-aminopropyl ether) (PEA) is used to assist carbon coating, which leads to a uniform carbon coating on the Si surface and the formation of a cross-linked carbon structure. As a result, the obtained Si/C electrode (Si70 P/C) maintains a reversible capacity of 1110 mAh g−1 at the 200th cycle at a current rate of 0.2C. Moreover, based on SEM/TEM observation and electrochemical characterization, the hypothetical action mechanism of PEA is also discussed.