It is crucial to enhance the rate capability of the titanium-based materials for fulfilling their promising potential as the anode materials of sodium-ion bat-teries(SIBs).Herein,Mn-doped sodium titanate(Mn-NTO)nanowi...It is crucial to enhance the rate capability of the titanium-based materials for fulfilling their promising potential as the anode materials of sodium-ion bat-teries(SIBs).Herein,Mn-doped sodium titanate(Mn-NTO)nanowires with homogeneously distributed ultrathin carbon nanosheets(Mn-NTO@C)are syn-thesized by a one-step salt-template-assisted method,showing much-enhanced power density.The as-prepared Mn-NTO@C demonstrates the realization of hybrid energy storage,which reconciles the diffusion-controlled behavior with the pseudocapacitive-controlled behavior.It has been revealed that the Mn heteroatoms can raise the proportion of Na_(2)Ti_(3)O_(7) phase with the expanded crystal lattice,facilitating the diffusion-controlled insertion/extraction process of sodium ions.Meanwhile,the hybrid morphology of Mn-NTO nanowires and carbon nanosheets provides a promoted structure stability.Asaresult,theassem-bled Na||Mn-NTO@C half-cells work well at an extreme current density of 24 A g^(−1) for 10000 cycles with a capacity retention of 95.2%.Moreover,the Mn-NTO@C||Na _(3) V_(2)(PO_(4))_(3)(NVP)full cells exhibit an attenuation of only 0.0015%per cycle at 20 A g^(−1) for over 10000 cycles,and the energy density and power density of the full cells reachan ultrahigh level of 262 Wh kg−1 and 16.3 kW kg−1,respectively.展开更多
基金This study was financially supported by the National Key Technologies R&D Program of China(Grant No.2018YFA900)the National Natural Science Foundation of China(51872012)the Fundamental Research Funds for the Central Universities.
文摘It is crucial to enhance the rate capability of the titanium-based materials for fulfilling their promising potential as the anode materials of sodium-ion bat-teries(SIBs).Herein,Mn-doped sodium titanate(Mn-NTO)nanowires with homogeneously distributed ultrathin carbon nanosheets(Mn-NTO@C)are syn-thesized by a one-step salt-template-assisted method,showing much-enhanced power density.The as-prepared Mn-NTO@C demonstrates the realization of hybrid energy storage,which reconciles the diffusion-controlled behavior with the pseudocapacitive-controlled behavior.It has been revealed that the Mn heteroatoms can raise the proportion of Na_(2)Ti_(3)O_(7) phase with the expanded crystal lattice,facilitating the diffusion-controlled insertion/extraction process of sodium ions.Meanwhile,the hybrid morphology of Mn-NTO nanowires and carbon nanosheets provides a promoted structure stability.Asaresult,theassem-bled Na||Mn-NTO@C half-cells work well at an extreme current density of 24 A g^(−1) for 10000 cycles with a capacity retention of 95.2%.Moreover,the Mn-NTO@C||Na _(3) V_(2)(PO_(4))_(3)(NVP)full cells exhibit an attenuation of only 0.0015%per cycle at 20 A g^(−1) for over 10000 cycles,and the energy density and power density of the full cells reachan ultrahigh level of 262 Wh kg−1 and 16.3 kW kg−1,respectively.
