Regulating Ni 3 d ‐O 2 p Orbital Interaction with Position‐Isomer Organic Lithiation Additive for High‐Voltage LiNi 0.8 Co 0.1 Mn 0.1 O 2 Cathode

ABSTRACT High‐voltage nickel‐rich layered oxide cathodes have attracted much attention due to their high capacity and elevated voltage plateau. However, the intrinsic Ni 3 d ‐O 2 p orbital overlapping promotes lattice oxygen release during the Ni valence transition, thereby accelerating structural degradation and interfacial parasitic reactions. Herein, we found that the position‐isomer slurry additive lithium 2‐thiopheneboron (2LTB) suppresses Ni‐O orbital overlap by enhancing the coordination of its Li, B, O, and S atoms with Ni and O in the cathode lattice, thereby stabilizing lattice oxygen at both the initial and deep discharge states. Electroactive 2LTB can form a thin and robust cathode electrolyte interface (CEI) that enhances Li + diffusion dynamics while alleviating transition metal dissolution, irreversible phase transformation, gas evolution and electrolyte invasion under high voltage. Consequently, LiNi 0.8 Co 0.1 Mn 0.1 O 2 ||Li cells with 1.5 wt.% 2LTB addition exhibits exceptional cycling performances, retaining 82.92% capacity retention after 450 cycles at 1 C and 76.09% after 800 cycles at 5 C under 4.5 V. A 1000‐mAh LiNi 0.8 Co 0.1 Mn 0.1 O 2 ‐2LTB||graphite pouch cell maintains 81.34% capacity retention after 700 cycles. Our findings establish a versatile framework for leveraging lithiation reagents to regulate orbital interactions, providing both mechanistic insights and practical guidance for the development of high‐voltage lithium‐ion batteries.