Layered transition metal(TM)oxides have gained significant attention for achieving high specific capac-ity and energy density utilizing the lattice oxygen redox for sodium-ion batteries.However,the highly oxidized lat...Layered transition metal(TM)oxides have gained significant attention for achieving high specific capac-ity and energy density utilizing the lattice oxygen redox for sodium-ion batteries.However,the highly oxidized lattice oxygen cannot be fully reduced due to irreversible structural deformation,phase tran-sition,and sluggish kinetics.Herein,the Cobalt(Co)content was tuned to synthesize a P2/P3-biphasic layered oxide cathode Na_(0.72)Li_(0.24)Co_(0.12)Mn_(0.64)O_(2)(NLM-Co12%),which exhibits pronounced lattice oxygen activity,leading to exceptional capacity and improved cyclability with superior structural stability.The distinct honeycomb ordering induces highly delocalizedπ-type interactions that generate additional elec-tron holes on oxygen,providing a record energy density and specific capacity of 767.98 Wh kg^(-1)and 287.19 mAh g^(-1),respectively.The strategic incorporation of Co in the TM layers mitigates the sluggish kinetics during the electrochemical reactions and improves the diffusion kinetics.The addition of elec-tron holes on Oxygen(O)is comprehensively investigated through different electrochemical and state-of-the-art spectroscopic techniques.Furthermore,in situ-XRD reveals the phase transition during Na^(+)insertion/extraction is eliminated due to the synergistic effect of the P2/P3 biphasic structure achieving superior structural stability.Benefiting from the superstructure ordering and P2/P3 biphasic structure,the NLM-Co12%electrode demonstrates simultaneously high lattice-oxygen activity and excellent structural stability,thus resulting in remarkable energy density and specific capacity.展开更多
Potassium-ions batteries(PIBs)are attracting increasing attention as up-and-coming youngster in largescale grid-level energy storage benefiting from its low-cost and high energy density.Nevertheless,enough researches ...Potassium-ions batteries(PIBs)are attracting increasing attention as up-and-coming youngster in largescale grid-level energy storage benefiting from its low-cost and high energy density.Nevertheless,enough researches regarding indispensable cathode materials for PIBs are badly absent.Herein,we synthesize K-deficient layered manganese-based oxides(P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2))and investigate them as cathode of PIBs for the first time.As the newcomer of potassium-containing layered manganese-based oxides(K_(x)MnO_(2))group,P2-K_(0.21)MnO_(2) delivers high discharge capacity of 99.3 mAh g^(-1) and P3-K_(0.23)MnO_(2) exhibits remarkable capacity retention rate of 75.5%.Besides,in-situ XRD and ex-situ XRD measurements reveal the reversible phase transition of P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2) with the potassium-ions extraction and reinsertion,respectively.This work contributes to a better understanding for the potassium storage in K-deficient layered K_(x)MnO_(2)(x≤0.23),possessing an important basic scientific significance for the exploitation and application of layered K_(x)MnO_(2) in PIBs.展开更多
基金supported by the National Key R&D Program of China(2024YFE0209300)the National Natural Science Foun-dation of China(Nos.52072282,52150710537,and 52127816)+2 种基金the National Natural Science Foundation of Hubei Province(No.2023AFB230)the Fundamental Research Funds for the Central Universities(No.WUT:3120624473)the Postdoctoral Fellow-ship Program of CPSF(No.GZC20241292).
文摘Layered transition metal(TM)oxides have gained significant attention for achieving high specific capac-ity and energy density utilizing the lattice oxygen redox for sodium-ion batteries.However,the highly oxidized lattice oxygen cannot be fully reduced due to irreversible structural deformation,phase tran-sition,and sluggish kinetics.Herein,the Cobalt(Co)content was tuned to synthesize a P2/P3-biphasic layered oxide cathode Na_(0.72)Li_(0.24)Co_(0.12)Mn_(0.64)O_(2)(NLM-Co12%),which exhibits pronounced lattice oxygen activity,leading to exceptional capacity and improved cyclability with superior structural stability.The distinct honeycomb ordering induces highly delocalizedπ-type interactions that generate additional elec-tron holes on oxygen,providing a record energy density and specific capacity of 767.98 Wh kg^(-1)and 287.19 mAh g^(-1),respectively.The strategic incorporation of Co in the TM layers mitigates the sluggish kinetics during the electrochemical reactions and improves the diffusion kinetics.The addition of elec-tron holes on Oxygen(O)is comprehensively investigated through different electrochemical and state-of-the-art spectroscopic techniques.Furthermore,in situ-XRD reveals the phase transition during Na^(+)insertion/extraction is eliminated due to the synergistic effect of the P2/P3 biphasic structure achieving superior structural stability.Benefiting from the superstructure ordering and P2/P3 biphasic structure,the NLM-Co12%electrode demonstrates simultaneously high lattice-oxygen activity and excellent structural stability,thus resulting in remarkable energy density and specific capacity.
基金support from the Key Project of Guangdong Province Nature Science Foundation (No. 2017B030311013)the Scientific and Technological Plan of Guangdong Province, Guangzhou and Qingyuan City, China (Nos. 2019B090905005, 2019B090911004, 2017B020227009, 2019DZX008, 2019A004)+2 种基金the financial support from the National Key R&D Program of China (2018YFB1502600)the National Natural Science Foundation of China (No. 51922042 and 51872098)the Sino-Singapore International Joint Research Institute (SSIJRI), Guangzhou 510700, China.
文摘Potassium-ions batteries(PIBs)are attracting increasing attention as up-and-coming youngster in largescale grid-level energy storage benefiting from its low-cost and high energy density.Nevertheless,enough researches regarding indispensable cathode materials for PIBs are badly absent.Herein,we synthesize K-deficient layered manganese-based oxides(P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2))and investigate them as cathode of PIBs for the first time.As the newcomer of potassium-containing layered manganese-based oxides(K_(x)MnO_(2))group,P2-K_(0.21)MnO_(2) delivers high discharge capacity of 99.3 mAh g^(-1) and P3-K_(0.23)MnO_(2) exhibits remarkable capacity retention rate of 75.5%.Besides,in-situ XRD and ex-situ XRD measurements reveal the reversible phase transition of P2-K_(0.21)MnO_(2) and P3-K_(0.23)MnO_(2) with the potassium-ions extraction and reinsertion,respectively.This work contributes to a better understanding for the potassium storage in K-deficient layered K_(x)MnO_(2)(x≤0.23),possessing an important basic scientific significance for the exploitation and application of layered K_(x)MnO_(2) in PIBs.
