摘要
Jahn-Teller distortion(JTD)remains a fundamental bottleneck for transition metal oxides(TMOs)in electrochemical energy storage,where the e_(g)-orbital single-electron occupancy induces irreversible octahedral collapse and rapid capacity fading.Here,we pioneer an itinerant-electron-mediated dynamic suppression strategy that fundamentally reshapes the JTD evolution pathway throughπ-d orbital hybridization engineering.By constructing reduced graphene oxide/TMO heterointerfaces(rGO/MO_(x),M=Fe/Ni/Mn),localized 3d electrons are transformed into delocalized itinerant states,which(1)eliminate e_(g)-band degeneracy via orbital repopulation and(2)establish an electron density buffer layer to neutralize lattice strain.This electronic regulation enables ultrafast Na^(+)diffusion kinetics(508.3 F g^(−1)at 1 A g^(−1)→304.6 F g^(−1)at 20 A g^(−1))and near-zero lattice deformation(91.07%capacitance retention after 20,000 cycles).Synchrotron-based X-ray absorption spectroscopy and density functional theory calculations reveal that itinerant electron dynamics actively decouple the Mn^(3+)d^(4)electronic configuration from JTD triggering,leading to a dramatic suppression of octahedral distortion compared to the conventional MnO_(2).The proposed electron delocalization-to-lattice stabilization paradigm opens a universal route to design distortion-resistant electrodes for high-power energy storage systems.
基金
Financial support from the National Natural Science Foundation of China(grant no.U20A20154,22279005,22379006,21575016)
the National Program for Support of Top-notch Young Professionals is gratefully acknowledged
technical support from the Xi’an Advanced Computing Center
