Low specific capacitances and/or limited working potential (≤4.5 V). of the prevalent carbon-based positive electrodes as the inborn bottleneck seriously hinder practical advancement of lithium-ion capacitors. Thus, breakthroughs in enhancement of both specific capacitances and upper cutoff potentials are enormously significant for high-energy density lithium-ion capacitors. Herein, we first meticulously design and scalably fabricate a commercializable fluorine-doped porous carbon material with competitive tap density, large active surface, appropriate aperture distribution, and promoted affinity with the electrolyte, rendering its abundant electroactive inter-/surface and rapid PF₆^- transport. Theoretical calculations authenticate that fluorine-doped porous carbon possesses lower PF₆^- adsorption energy and stronger interaction with PF₆^-. Thanks to the remarkable structural/compositional superiority, when served as a positive electrode toward lithium-ion capacitors, the commercial-level fluorine-doped porous carbon showcases the record-breaking electrochemical properties within a wider working window of 2.5–5.0 V (vs Li/Li⁺) in terms of high-rate specific capacitances and long-duration stability, much superior to commercial activated carbon. More significantly, the 4.5 V-class graphite//fluorine-doped porous carbon lithium-ion capacitors are first constructed and manifest competitive electrochemical behaviors with long-cycle life, modest polarization, and large energy density. Our work provides a commendable positive paradigm and contributes a major step forward in next-generation lithium-ion capacitors and even other high-energy density metal-ion capacitors.

The orthorhombic CuNb₂O₆ (O–CNO) is established as a competitive anode for lithium-ion capacitors (LICs) owing to its attractive compositional/structural merits. However, the high-temperature synthesis (>900 ℃) and controversial charge-storage mechanism always limit its applications. Herein, we develop a low-temperature strategy to fabricate a nano-blocks-constructed hierarchical accordional O–CNO framework by employing multilayered Nb₂CT_x as the niobium source. The intrinsic stress-induced formation/transformation mechanism of the monoclinic CuNb₂O₆ to O–CNO is tentatively put forward. Furthermore, the integrated phase conversion and solid solution lithium-storage mechanism is reasonably unveiled with comprehensive in(ex) situ characterizations. Thanks to its unique structural merits and lithium-storage process, the resulted O–CNO anode is endowed with a large capacity of 150.3 mAh g⁻¹ at 2.0 A g⁻¹, along with long-duration cycling behaviors. Furthermore, the constructed O–CNO-based LICs exhibit a high energy (138.9 Wh kg⁻¹) and power (4.0 kW kg⁻¹) densities with a modest cycling stability (15.8% capacity degradation after 3000 consecutive cycles). More meaningfully, the in-depth insights into the formation and charge-storage process here can promote the extensive development of binary metal Nb-based oxides for advanced LICs.