摘要：As promising,low-cost alternatives of lithiumion batteries for large-scale electric energy storage,sodiumion batteries(SIBs)have been studied by many ***,the relatively large size of Na+leads to sluggish diffusion kinetics and poor cycling stability in most cathode materials,restricting their further *** this work,we demonstrated a novel K+-intercalated Mn/Ni-based layered oxide material(K0.7Mn0.7Ni0.3O2,denoted as KMNO)with stabilized and enlarged diffusion channels for high energy density SIBs.A spontaneous ion exchange behavior in forming K0.1Na0.7Mn0.7Ni0.3O2between the KMNO electrode and the sodium ion electrolyte was clearly revealed by in situ X-ray diffraction and ex situ inductively coupled plasma *** interlayer space varied from 6.90 to 5.76?,larger than that of Na0.7Mn0.7Ni0.3O2(5.63?).The enlarged ionic diffusion channels can effectively increase the ionic diffusion coefficient and simultaneously provide more K+storage sites in the product *** a proof-of-concept application,the SIBs with the as-prepared KMNO as a cathode display a high reversible discharge capacity(161.8 mA h g-1at0.1 A g-1),high energy density(459 W h kg-1)and superior rate capability of 71.1 mA h g-1at 5 A *** work demonstrates that the K+pre-intercalation strategy endows the layered metal oxides with excellent sodium storage performance,which provides new directions for the design of cathode materials for various batteries.

摘要：Flexible lithium-sulfur(Li-S)batteries are considered one of the most promising candidates for highenergy-density storage devices in wearable ***,the safety problem severely restricts the practical application of Li-S batteries because of the possible occurrence of thermal runaway caused by battery short circuits and combustible components,particularly under bending *** development of advanced separators that can suppress lithium dendrite growth and are incombustible is the key to improving the safety of flexible Li-S *** this work,a nonflammable multifunctional Janus separator with self-extinguishing capability,high thermal stability,high thermal conductivity,good electrolyte infiltration,uniform lithium deposition,and efficient polysulfide shuttling inhibition,is *** separator is composed of polyacrylonitrile(PAN)fiber and decabromodiphenyl ethane(DBDPE)membrane as well as functional layers of boron nitride(BN)for suppressing lithium dendrite growth and reduced graphene oxide(rGO)for accelerating the sulfur convention *** a result,the Li-S battery with a sulfur mass loading of2.7 mg cm^(-2) delivers a specific capacity of 916.8 mA h g^(-1) after100 cycles at 0.1 C and maintains a stable performance during intermittent thermal ***,the Li-S pouch cell with a sulfur mass loading of 8 mg exhibits a high capacity of6.3 mA h under bending conditions.