Abstract
As an alternative for lithium-ion batteries(LIBs),sodium-ion batteries(SIBs)have lately received tremen-dous interest due to their abundant reserves as well as low cost.Nevertheless,the lack of suitable an-ode materials severely hinders the application of sodium-ion batteries.TiS2 is elected as a representative material owing to its unique layered structure.But it always suffers from capacity fade due to poor elec-trochemical kinetics and structural stability.In this work,we fabricate a pre-potassiated TiS2 as a host material for sodium storage by an electrochemical pre-potassiation strategy.The intercalation/extraction mechanism,structural changes and reaction kinetics are completely investigated to reveal the outstand-ing electrochemical property of pre-potassiated TiS2 electrode.It turns out that the large interlayer space of pre-potassiated TiS2 is conducive to the diffusion of sodium ions,inducing the reduction of entropic barrier for the electrochemical reactions.In addition,the pre-potassiated host structure is still firmly maintained upon repeated cycles.Therefore,the pre-potassiated TiS2 presents superior rate capability(165.9 mA h g-1 at 1 C and 132.1 mA h g-1 at 20 C)and long-term cycling stability(85.3％capacity retention at 5 C after 500 cycles)for SIBs.This research provides an avenue to construct long-life sodium energy storage systems based on pre-potassiated TiS2.
基金项目
NSAF joint Fund(U1830106)
Sci-ence and Technology Innovation 2025 Major Program of Ningbo(2018B10061)
国家自然科学基金(U1632114)
国家自然科学基金(51901205)
KCWong Magna Fund in Ningbo Uni-versity()
NETL
NSTL
万方数据