Dynamic Multi-Physics Behaviors and Performance Loss of Cylindrical Batteries Upon Low-Velocity Impact Loading

In challenging operational environments,Lithium-ion batteries(LIBs)inevitably experience mechanical stresses,including impacts and extrusion,which can lead to battery damage,failure,and even the occurrence of fire and explosion incidents.Consequently,it is imperative to investigate the safety performance of LIBs under mechanical loads.This study is grounded in a more realistic coupling scenario consisting of electrochemical cycling and low-velocity impact.We systematically and experimentally uncovered the mechanical,electrochemical,and thermal responses,damage behavior,and corresponding mechanisms under various conditions.Our study demonstrates that higher impact energy results in increased structural stiffness,maximum temperature,and maximum voltage drop.Furthermore,heightened impact energy significantly influences the electrical resistance parameters within the internal resistance.We also examined the effects of State of Charge(SOC)and C-rates.The methodology and experimental findings will offer insights for enhancing the safety design,conducting risk assessments,and enabling the cascading utilization of energy storage systems based on LIBs.

A Comparative Investigation of Single Crystal and Polycrystalline Ni-Rich NCMs as Cathodes for Lithium-Ion Batteries

Nickel-rich LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM,1-x-y≥0.6)is known as a promising cathode material for lithium-ion batteries since its superiority of high voltage and large capacity.However,polycrystalline Ni-rich NCMs suffer from poor cycle stability,limiting its further application.Herein,single crystal and polycrystalline LiNi_(0.84)Co_(0.07)Mn_(0.09)O_(2)cathode materials are compared to figure out the relation of the morphology and the electrochemical storage performance.According to the Li^(+)diffusion coefficient,the lower capacity of single crystal samples is mainly ascribed to the limited Li+diffusion in the large bulk.In situ XRD illustrates that the polycrystalline and single crystal NCMs show a virtually identical manner and magnitude in lattice contraction and expansion during cycling.Also,the electrochemically active surface area(ECSA)measurement is employed in lithium-ion battery study for the first time,and these two cathodes show huge discrepancy in the ECSA after the initial cycle.These results suggest that the single crystal sample exhibits reduced cracking,surface side reaction,and Ni/Li mixing but suffers the lower Li^(+)diffusion kinetics.This work offers a view of how the morphology of Ni-rich NCM effects the electrochemical performance,which is instructive for developing a promising strategy to achieve good rate performance and excellent cycling stability.

Sulfur-containing compounds as electrolyte additives for lithium-ion batteries

Originating from“rocking-chair concept”,lithium-ion batteries(LIBs)have become one of the most important electrochemical energy storage technolo-gies,which have largely impacted our daily life.The utilization of electrolyte additives in small quantities(≤5%by wt or vol)has been long viewed as an economical and efficient approach to regulate the properties of electrolyte and electrode–electrolyte interphases and consequently improve the cycling perfor-mance of LIBs.Among all the kinds of electrolyte additives,sulfur-containing compounds have gained significant attention due to their unique features in building stable electrode–electrolyte interphases and protect battery cells from overcharging.In this work,advances and progresses of sulfur-containing addi-tives used in LIBs are overviewed,with special attention paid to the working mechanisms of these electrolyte additives.Particularly,four representative sulfur-containing compounds(i.e.,1,3-propane sultone,prop-1-ene-1,3-sultone,1,3,2-dioxathiolane-2,2-dioxide,and ethylene sulfite)are comparatively dis-cussed concerning their impact on electrode–electrolyte interphases and cell per-formances.Future work on the development of sulfur-containing compounds as functional electrolyte additives is also provided.The present review is antici-pated to be not only a base document to access the status quo in this research domain but also a guideline to select specialized additives and electrolytes for practical applications.

Sol-gel Synthesis and Electrochemical Performance of Li4-xMgxTi5-xZrxO12 Anode Material for Lithium-ion Batteries

The anode materials Li4-xMgxTi5-xZrxO12（x=0, 0.05, 0.1） were successfully synthesized by sol-gel method using Ti（OCaH9）4, CH3COOLi·2H2O, MgCl2·6H2O and Zr（NO3）3·6H2O as raw materials. The crystalline structure, morphology and electrochemical properties of the as-prepared materials were characterized by XRD, SEM, cyclic voltammograms （CV）, electrochemical impedance spectroscopy （EIS） and charge-discharge cycling tests. The re- sults show that the lattice parameters of the Mg-Zr doped samples are slightly larger than that of the pure LiaTi5Oi2, and Mg-Zr doping does not change the basic Li4Ti5O2 structure. The rate capability of Li4-xMgxTi5-xZrxO12 （x= 0.05, 0.1） electrodes is significantly improved due to the expansile Li＋ diffusion channel and reduced charge transfer resistance. In this study, Li3.95Mg0.05Ti4.95Zr0.05O12 represented a relatively good rate capability and cycling stability, after 400 cycles at 10 C, the discharge capacity retained as 134.74 mAh·g-1 with capacity retention close to 100%. The excellent rate capability and good cycling performance make Li3.95Mg0.05Ti4.95Zr0.05O12 a promising anode material in lithium-ion batteries.

Enhanced cycling stability of antimony anode by downsizing particle and combining carbon nanotube for high-performance sodium-ion batteries

Antimony(Sb)nanoparticles(SbNP)encapsulated in multiwalled carbon nanotubes(MWCNTs)matrix has been fabricated by a facile two-step ball milling strategy,including a sand milling process to prepare Sb nanoparticles and following high-energy ball milling to synthesize SbNP-MWCNT composite.As an anode material for sodium-ion batteries(SIBs),the SbNP-MWCNT composite with high Sb content(80%)can deliver a reversible capacity of 471.1 mA hg^(-1)at 50 mA g^(-1)with an initial coulombic efficiency of 73.5%,excellent cycling stability(94.1%capacity retention at 800 mA g^(-1))and high rate capability(210.7 mA h g^(-1)at 3200 mA g^(-1)).The excellent electrochemical performance of the SbNP-MWCNT composite results from the synergistic effect of downsizing Sb particles and combining MWCNTs.

Ultralong-life lithium metal batteries enabled by decorating robust hybrid interphases on 3D layered framworks

Stable solid-electrolyte interphase(SEI)is crucial for advanced development of lithium metal batteries.However,the continuous collapse and reconstruction of SEI will deplete fresh Li and electrolytes upon cycling,leading to irreversible capacity loss.Herein,we addressed this issue by pre-formation of artificial robust hybrid interphase on a 3D layered graphene/lithium metal framework,in which is constructed by LiF associated with Li2TiF 6generated by the in-situ reaction between the surfacial lithium and titanium fluoride contained electrolytes.The as-obtained interphase can maintain the structure integrality and avoid continuous consumption of the fresh Li and electrolytes.As a consequence,the Li symmetric cells achieve high-efficiency Li deposition and stable cycling over 3600 h.When paired with LiFePO_(4)cathodes,the coin cells exhibit long lifespan(>800 cycles)with almost 88.3%retention of the initial capacity.