Performance of n-type silicon/silver composite anode material in lithium ion batteries: A study on effect of work function matching degree

In this paper, two types of silicon (Si) particles ball-milled from n-type Si wafers, respectively, with resistivity values of 1 Ω·cm and 0.001 Ω·cm are deposited with silver (Ag). The Ag-deposited n-type 1-Ω·cm Si particles (n1-Ag) and Ag-deposited n-type 0.001-Ω·cm Si particles (n0.001-Ag) are separately used as an anode material to assemble coin cells, of which the electrochemical performances are investigated. For the matching of work function between n-type 1-Ω·cm Si (n1) and Ag, n1-Ag shows discharge specific capacity of up to 683 mAh·g^-1 at a current density of 8.4 A·g^-1, which is 40% higher than that of n0.001-Ag. Furthermore, the resistivity of n1-Ag is lower than half that of n0.001-Ag. Due to the mismatch of work function between n-type 0.001-Ω·cm Si (n0.001) and Ag, the discharge specific capacity of n0.001-Ag is 250.2 mAh·g^-1 lower than that of n1-Ag after 100 cycles.