Unveiling the Effects of Cr Single Atoms with Controllable Configurations on Solid Electrolyte Interphase and Storage Mechanism of Sodium Ions
Chong Wang, Bohan Li, Wanci Shen, Feiyu Kang, Zheng‐Hong Huang, Ruitao Lv
Abstract
Abstract Single atomic metal (SAM) doping is reported as an effective strategy to promote the electrochemical property of carbon‐based anode materials for high‐power sodium‐ion batteries (SIBs). However, the effects of SAM with different configurations on solid electrolyte interphase (SEI) and energy storage mechanism of Na + are not revealed. Herein, Cr single atoms (CrSAs) are reported with controllable configurations (Cr–N 4 or Cr–N 2 ) implanted on the N, P co‐doped carbon (NPC) anode materials (denoted as CrN 4 SAs/NPC or CrN 2 SAs/NPC). The CrN 4 SAs/NPC anode displays a high specific capacity (318.2 mAh g −1 at 0.05 A g −1 ) and outstanding rate performance (145.1 mAh g −1 at 5 A g −1 ), better than those of CrN 2 SAs/NPC and NPC. The superiority is originated from the difference of SEI and the energy storage mechanism of sodium ions during electrochemical process, which are unveiled through ex situ characterization and theoretical calculation. The full cell assembled with CrN 4 SAs/NPC anode and Na 3 V 2 (PO 4 ) 2 F 3 @C cathode displays a high energy density at a high power density.