Electrode-compatible fluorine-free multifunctional additive regulating solid electrolyte interphase and solvation structure for high-performance lithium-ion batteries

The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.

Unveiling the effect of amino acids on the crystallization pathways of methylammonium lead iodide perovskites

Multifunctional additives are widely used to improve crystallization and to passivate defects in perovskite solar cells. The roles of these additives are usually related to the various functional groups contained in such additives. Here, we introduce a serious of analogues of amino acids into methylammonium lead iodide perovskites and find they play different roles in the crystallization process despite the fact that these additives share exactly the same terminal groups, namely one amino group and one carboxyl group. The corresponding crystallization pathways are established for the first time via monitoring the time-resolved phase formation and transformation. We find that avoiding the rapid formation of perovskites from precursor solution can facilitate the uniform nucleation and growth of perovskite crystals with enhanced crystallinity and reduced defects. Further, we find the different crystallization behaviors probably arise from the inherent structural characteristic of these additives, leading to different interactions in the precursors. This study unveils the effects of amino acids on the liquid–solid crystallization process and helps better understand the role of multifunctional additives beyond their functional groups.

Antimony Potassium Tartrate Stabilizes Wide-Bandgap Perovskites for Inverted 4-T All-Perovskite Tandem Solar Cells with Efficiencies over 26%

Wide-bandgap(WBG)perovskites have been attracting much attention because of their immense potential as a front light-absorber for tandem solar cells.However,WBG perovskite solar cells(PSCs)generally exhibit undesired large open-circuit voltage(VOC)loss due to light-induced phase segregation and severe non-radiative recombination loss.Herein,antimony potassium tartrate(APTA)is added to perovskite precursor as a multifunctional additive that not only coordinates with unbonded lead but also inhibits the migration of halogen in perovskite,which results in suppressed non-radiative recombination,inhibited phase segregation and better band energy alignment.Therefore,a APTA auxiliary WBG PSC with a champion photoelectric conversion efficiency of 20.35%and less hysteresis is presented.They maintain 80%of their initial efficiencies under 100 mW cm^(-2)white light illumination in nitrogen after 1,000 h.Furthermore,by combining a semi-transparent WBG perovskite front cell with a narrow-bandgap tin–lead PSC,a perovskite/perovskite four-terminal tandem solar cell with an efficiency over 26%is achieved.Our work provides a feasible approach for the fabrication of efficient tandem solar cells.

Synthesis and evaluation of a protic ionic liquid as a multifunctional lubricant additive

An oil soluble multifunctional protic ionic liquid(IL)was synthesized and its tribological and antioxidant properties in poly alpha olefin(PA04)were investigated.The tribological results demonstrated that the IL significantly reduced friction and wear of PA04.The PA04 blend with IL resulted in an induced oxidation time of 555 min which is 8.2 and 3.5 times higher than that of pure PA04 and PA04 with zinc dialkyl dithiophosphate(ZDDP)for the rotating pressure vessel oxidation test.It is likely that free nonylated diphenylamine acted as a radical scavenger to enhance antioxidant performance,while free bis(2-ethylhexyl)phosphate was more prone to adsorb and react with the metal surface to form a phosphorus-rich tribofilm in order to protect the rubbing surface.

A common polar dye additive as corrosion inhibitor and leveling agent for stable aqueous zinc-ion batteries

The industrial application of zinc-ion batteries is restricted by irrepressible dendrite growth and side reactions that resulted from the surface heterogeneity of the commercial zinc electrode and the thermodynamic spontaneous corrosion in a weakly acidic aqueous electrolyte.Herein,a common polar dye,Procion Red MX-5b,with high polarity and asymmetric charge distribution is introduced into the zinc sulfate electrolyte,which can not only reconstruct the solvation configuration of Zn2þand strengthen hydrogen bonding to reduce the reactivity of free H_(2)O but also homogenize interfacial electric field by its preferentially absorption on the zinc surface.The symmetric cell can cycle with a lower voltage hysteresis(78.4 mV)for 1120 times at 5 mA cm^(−2)and Zn//NaV_(3)O_(8)·1.5H_(2)O full cell can be cycled over 1000 times with high capacity(average 170 mAh g^(−1))at 4 A g^(−1)in the compound electrolyte.This study provides a new perspective for additive engineering strategies of aqueous zinc-ion batteries.