Beyond Conversion Chemistry:Unlocking a Cooperative Solid-Solution-Capacitive Sodium-Storage Mechanism in Nickel PhosphideOA
Nickel-rich nickel phosphide(Ni_(2)P)has emerged as a promising sodium-ion battery anode owing to its high theoretical capacity and intrinsic electronic conductivity,yet its charge storage chemistry remains controversial and is often oversimplified as a conversion reaction.Herein,we design a freestanding Ni_(2)P composite electrode composed of ultrasmall Ni_(2)P nanocrystals embedded within a phosphorus-doped,graphene-like porous carbon matrix.Comprehensive in-situ and ex-situ analyses unequivocally demonstrate an interstitial solidsolution mechanism,wherein Na+ions reversibly occupy lattice interstitials via(111)-oriented interplanar channels,inducing reversible lattice breathing without phase transformation.This bulk intercalation process is synergistically coupled with a substantial pseudocapacitive contribution,establishing a cooperative dual-mode storage mechanism.Benefiting from this solid-solution-capacitive chemistry,the electrode delivers a high reversible capacity(≈560 mAh g^(-1)),outstanding rate capability(135 mAh g^(-1)at 10 A g^(-1)),and exceptional long-term stability(263 mAh g^(-1)after 2000 cycles).When paired with a Na3V2(PO4)3@C cathode,the full cell achieves a high-energy density of 245 Wh kg^(-1).This work establishes solid-solution-capacitive coupling as a general paradigm for designing high-rate and durable sodium-ion battery anodes.
Jiaqin Liu;Tongzhen Wang;Jie Yang;Yulei Li;Zhaoqian Li;Jiewu Cui;Yan Yu;Yucheng Wu
State Key Laboratory of Chemical Resource Engineering,College of Chemistry,Beijing University of Chemical Technology,Beijing 100029,People''s Republic of China School of New Energy Engineering,Hefei Institute of Technology,Hefei 238706,People''s Republic of ChinaSchool of Mechanical Engineering,School of Materials Science and Engineering,Engineering Research Center of Advanced Composite Materials Design&Application of Anhui Province,Hefei University of Technology,Hefei 230009,People''s Republic of ChinaSchool of Mechanical Engineering,School of Materials Science and Engineering,Engineering Research Center of Advanced Composite Materials Design&Application of Anhui Province,Hefei University of Technology,Hefei 230009,People''s Republic of ChinaSchool of Mechanical Engineering,School of Materials Science and Engineering,Engineering Research Center of Advanced Composite Materials Design&Application of Anhui Province,Hefei University of Technology,Hefei 230009,People''s Republic of ChinaSchool of New Energy Engineering,Hefei Institute of Technology,Hefei 238706,People''s Republic of ChinaSchool of Mechanical Engineering,School of Materials Science and Engineering,Engineering Research Center of Advanced Composite Materials Design&Application of Anhui Province,Hefei University of Technology,Hefei 230009,People''s Republic of ChinaDepartment of Materials Science and Engineering,CAS Key Laboratory of Materials for Energy Conversion,Hefei National Research Center for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026,People''s Republic of ChinaSchool of Mechanical Engineering,School of Materials Science and Engineering,Engineering Research Center of Advanced Composite Materials Design&Application of Anhui Province,Hefei University of Technology,Hefei 230009,People''s Republic of China School of New Energy Engineering,Hefei Institute of Technology,Hefei 238706,People''s Republic of China
信息技术与安全科学
Sodium-ion batteryAnodeNi_(2)PSolid-solutionPseudocapacitive
《Nano-Micro Letters》 2026 (7)
P.810-824,15
supported by the National Natural Science Foundation of China(52372187,52394170,52394171)the Fundamental Research Funds for the Central Universities of China(buctrc202503,JZ2024HGTG0291,PA2025GDSK0054)the Anhui Provincial Special Support Program for Innovative Leading Talents(Z2023TP0002)the Higher Education Discipline Innovation Project“New Materials and Technology for Clean Energy”(B18018)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA21000000)the Anhui Provincial Natural Science Foundation(2408085MB029)the Hefei Institute of Technology Talent Research Fund(2025KY41).
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