“…Although the insertion of A + will completely destroy the structure of M x P y , these materials have the highest capacity among all metal phosphides. M x P y with the alloy mechanism mainly include Sn 4 P 3 (3 × 3 + 15/4 × 4 Na, represents the "(3y + bx)A" in (4)), [88][89][90][91][92] Sn 4 P 3 (3 × 3 + 1 × 4 K), [93] Sn 4 P 3 (3 × 3 + 4 × 4 Li), [94,95] SnP 3 (3 × 3 + 15/4 × 1 Na), [96,97] GeP 5 (3 × 5 + 22/5 × 1 Li), [98] GeP 5 (3 × 5 + 1 × 1 Na), [99,100] Ge 2 P 3 (3 × 3 + 2 × 22/5 Li), [101] Ge 2 P 3 (3 × 3 + 1 × 2 Na), [101] GeP 3 (3 × 3 + 1 × 22/5 Li), [102] GeP 3 (3 × 3 + 1 × 1 Na), [103] InP (1 × 1 + 13/3 × 1 Li), [104] ZnP 2 (2 × 3 + 1 × 1 Li), [105][106][107] [108,109] SiP 2 (2 × 3 + 1 × 15/4 Li), [110] Se 4 P 4 (4 × 3 + 4 × 2 Na). [111] For instance, Qian et al discovered that Sn 4 P 3 went through the alloy mechanism (Sn 4 P 3 + 24Na → Na 15 Sn 4 + 3Na 3 P) through ex situ XRD, and it exhibited great electrochemical performance with ≈86% retention of the initial capacity (850 mA h g −1 ) after 150 cycles.…”