Rational Construction of Heterostructures with n‐Type Anti‐Barrier Layer for Enhanced Electrochemical Energy Storage

Abstract As a type of 2D materials, layered double hydroxides (LDHs) have emerged as potential candidates for electrochemical energy storage materials. To address their challenges of limited active sites and sluggish charge transfer kinetics, etc., this work presents an ingenious synchronous topochemical pathway (STP) method that enables the in situ anchoring of numerous nanosized Co 9 S 8 on the rigid layers of LDHs. These n‐type anti‐barrier layers, generated by the ohmic contact between a quasi‐metal (Co 9 S 8 ) and n‐type semiconductor (LDHs), alter the energy band structure and electron states near the Fermi level, optimizing the intrinsic conductivity and deprotonation reaction barriers of LDH materials. The prepared NiCoAl‐LDHs@Co 9 S 8 (LCS) electrode exhibits remarkable electrochemical capacity (473.2 mAh g − ¹ at 1 A g − ¹) and operational stability (91.2% capacity retention after 20,000 cycles). Furthermore, an aqueous battery device constructed with LCS cathode and Fe‐Ni sulfide (FNS) anode demonstrates an impressive energy density of 118.5 Wh kg − ¹ at a power density of 800 W kg − ¹. This generalized structural design strategy achieves multiple enhancements in active sites, charge transfer efficiency, and structural stability of LDH materials, providing insights into the potential relationships between energy band and electrochemical performance in energy storage materials.