Fluorinated soft carbon as an ultra-high energy density potassium-ion battery cathode enabled by a ternary phase K_(x)FC

Fluorinated carbons(CFx)have been widely applied as lithium primary batteries due to their ultra-high energy density.It will be a great promise if CFx can be rechargeable.In this study,we rationally tune the C-F bond strength for the alkaline intercalated CFx via importing an electronegative weaker element K instead of Li.It forms a ternary phase K_(x)FC instead of two phases(LiF+C)in lithium-ion batteries.Meanwhile,we choose a large layer distance and more defects CFx,namely fluorinated soft carbon,to accommodate K.Thus,we enable CFx rechargeable as a potassium-ion battery cathode.In detail fluorinated soft carbon CF_(1.01) presents a reversible specific capacity of 339 mA h g^(-1)(797 Wh kg^(-1))in the 2nd cycle and maintains 330 mA h g^(-1)(726 Wh kg^(-1))in the 15th cycle.This study reveals the importance of tuning chemical bond stability using different alkaline ions to endow batteries with rechargeability.This work provides good references for focusing on developing reversible electrode materials from popular primary cell configurations.

Superfast and solvent-free core-shell assembly of sulfur/carbon active particles by hail-inspired nanostorm technology for high-energy-density Li-S batteries

The demand on low-carbon emission fabrication technologies for energy storage materials is increasing dramatically with the global interest on carbon neutrality.As a promising active material for metal-sulfur batteries,sulfur is of great interest due to its high-energy-density and abundance.However,there is a lack of industry-friendly and low-carbon fabrication strategies for high-performance sulfur-based active particles,which,however,is in critical need by their practical success.Herein,based on a hail-inspired sulfur nano-storm(HSN)technology developed in our lab,we report an energy-saving,solvent-free strategy for producing core-shell sulfur/carbon electrode particles(CNT@AC-S)in minutes.The fabrication of the CNT@AC-S electrode particles only involves low-cost sulfur blocks,commercial carbon nanotubes(CNT)and activated carbon(AC)micro-particles with high specific surface area.Based on the above core-shell CNT@AC-S particles,sulfur cathode with a high sulfur-loading of 9.2 mg cm^(-2) delivers a stable area capacity of 6.6 mAh cm^(-2) over 100 cycles.Furthermore,even for sulfur cathode with a super-high sulfur content(72 wt%over the whole electrode),it still delivers a high area capacity of 9 mAh cm^(-2) over50 cycles in a quasi-lean electrolyte condition.In a nutshell,this study brings a green and industryfriendly fabrication strategy for cost-effective production of rationally designed S-rich electrode particles.

A Li_(3)P nanoparticle dispersion strengthened ultrathin Li metal electrode for high energy density rechargeable batteries

Achievement of lithium(Li)metal anode with thin thickness(e.g.,≤30µm)is highly desirable for rechargeable high energy density batteries.However,the fabrication and application of such thin Li metal foil electrode remain challenging due to the poor mechanical processibility and inferior electrochemical performance of metallic Li.Here,mechanico-chemical synthesis of robust ultrathin Li/Li_(3)P(LLP)composite foils(~15µm)is demonstrated by employing repeated mechanical rolling/stacking operations using red P and metallic Li as raw materials.The in-situ formed Li+-conductive Li_(3)P nanoparticles in metallic Li matrix and their tight bonding strengthen the mechanical durability and enable the successful fabrication of free-standing ultrathin Li metal composite foil.Besides,it also reduces the electrochemical Li nucleation barrier and homogenizes Li plating/stripping behavior.When matching to high-voltage LiCoO_(2),the full cell with a low negative/positive(N/P)capacity ratio of~1.5 offers a high energy density of~522 W·h·kg^(-1) at 0.5 C based on the mass of cathode and anode.Taking into account its facile manufacturing,potentially low cost,and good electrochemical performance,we believe that such an ultrathin composite Li metal foil design with nanoparticle-dispersion-strengthened mechanism may boost the development of high energy density Li metal batteries.

A novel tin-graphite dual-ion battery based on the sodium-ion electrolyte with high energy density

Subject Code:E02With the support by the National Natural Science Foundation of China and the Chinese Academy of Sciences,the research team led by Prof.Tang Yongbing(唐永炳)at the Functional Thin Films Research Center,Shenzhen Institutes of Advanced Technology,Chinese Academy of Sciences,developed a novel tin-graphite dual-ion battery based on sodium-ion electrolyte with high energy density,which

A non-aqueous Li/organosulfur semi-solid flow battery

Non-aqueous flow batteries have attracted extensive attention due to the advantages of wide voltagewindow, high energy density and wide operating temperature and so on. Herein, tetramethylthiuramdisulfide （TMTD） with high intrinsic capacity （223 mAh/g） and high solubility （-1 mol/L in chloroform） isinvestigated as the positive active material of the non-aqueous LiJdisulfide semi-solid flow battery. Theelectrochemical activity and reversibility are investigated by cyclic voltammetry and linear scanvoltammetry. This Li/TMTD battery with a high cell voltage of 3.36 V achieves coulombic efficiency of 99%,voltage efficiency of 73% and energy efficiency of 72% at the current density of 5 mA/cm2 with activematerial concentration of 0.1 mol/L. Moreover, the LiJTMTD battery can operate for 100 cycles withoutobvious efficiency decay, indicating good stability.