Composite solid electrolyte of Na3PS4-PEO for all-solid-state SnS2/Na batteries with excellent interfacial compatibility between electrolyte and Na metal

High ionic conductivity and superior interfacial stability of solid electrolytes at the electrodes are crucial factors for high-performance all-solid-state sodium batteries. Herein, a composite solid electrolyte Na3PS4-polyethylene oxide is synthesized by the solution-phase reaction method with an improved ionic conductivity up to 9.4 × 10-5 S/cm at room temperature. Moreover, polyethylene oxide polymer layer is wrapped homogeneously on the surface of Na3PS4 particles, which could effectively avoid the direct contact between Na3PS4 electrolyte and sodium metal, thus alleviate their side reactions. We demonstrate that all-solid-state battery SnS2/Na with the composite solid electrolyte Na3PS4-polyethylene oxide delivers an enhanced electrochemical performance with 230 m Ah/g after 40 cycles.

Study on group intervention regarding interpersonal trust among college students with campus psychodrama

Purpose: To explore the interventional effects of campus psychodrama on improving the interpersonal trust among college students. Methods: 16 college students with low levels of interpersonal trust were selected to conduct 5 sessions of psychodrama therapy. Results: The subject group has gone through stages of ice breaking, performance, and sharing. Through group counseling with psychodrama, the social avoidance and distressful behaviors of the subjects have been alleviated, and their levels of interpersonal trust demonstrated notable change. Conclusion: Campus psychodrama is an effective group counseling approach for improving college students’ interpersonal trust.

Guest ions pre-intercalation strategy of manganese-oxides for supercapacitor and battery applications

Optimization of intrinsic structure of electrode materials plays decisive roles in promoting the development of energy storage systems to meet the fast-growing requirements in the market.Interlayer engineering has been proved to be an effective way to obtain adequate active sites,preferable ion diffusion channels and stable structure,thus enhance the performance of batteries.An in-depth understanding of the correlation among synthesis,structure and performance will significantly promote the development of excellent materials and energy storage devices.Therefore,in this review,recent advances in regards to cation preintercalation engineering in Mn-based electrode materials for rechargeable metal ion batteries are systematically summarized.Preintercalated guest cations can expand interlayer space to promote ion diffusion kinetics,serve as pillars to stabilize structure,control composition and valence to switch electrochemical behavior,thus improve the overall performance of secondary batteries.Moreover,the existing challenges and perspectives are provided for the interlayer engineering and its promotion to battery industry.

Boosting fast interfacial Li^(+)transport in solid-state Li metal batteries via ultrathin Al buffer layer

Na superionic conductor(NASICON)-type Li_(1.5)Al_(0.5)Ge_(0.5)P_(3)O_(12)(LAGP)solid state electrolytes(SSEs)have attracted significant interests thanks to the prominent ionic conductivity(>10^(–4)S·cm^(–1))at room temperature and superb stability in air.Unfortunately,its application has been hindered by the lithium dendrites and the intrinsic interfacial instability of LAGP towards metallic Li,etc.Herein,by magnetron sputtering(MS),an ultrathin Al film is deposited on the surface of the LAGP pellet(Al-LAGP).By in-situ alloying reaction,the spontaneously formed LiAl buffer layer inhibits the side reaction between LAGP SSEs and Li metal,induces the uniform distribution of interfacial electric field as well.Density functional theory(DFT)calculations demonstrate that the LiAl alloy surface promotes the diffusion of lithium atoms due to the lower energy barrier,thereby inhibiting the formation of lithium dendrites.Consequently,the Li/Al-LAGP-Al/Li symmetric cells show a low resistance of 210Ωand a durable lifespan over 1,200 h at a high current density of 0.1 mA·cm^(-2).Assembled all solid state lithium metal batteries(ASSLMBs)with LiFePO_(4)(LFP)cathode significantly improve cycle stability and rate performance,proving a promising stabilization strategy towards the NASIOCN type electrolyte/anode interface in solid state Li metal batteries.

Modulating surface cation vacancies of nickel-cobalt oxides as efficient catalysts for lithium-oxygen batteries

Rechargeable lithium-oxygen batteries(LOBs)have received incremental attention owing to their high energy density and applicability to mobile devices and electric vehicles.However,the lack of robust,low-cost,and environmentally benign bifunctional catalysts is a major impediment to the commercial application.The introduction of vacancies is one of the effective strategies to enhance the performance of cathode catalysts for lithium-oxygen batteries,but the preparation is complicated.In this work,needle-like microsphere cathode catalysts of nickel-cobalt oxide containing cationic vacancies are constructed by controlling the annealing temperature.It is demonstrated that the presence of cationic vacancies can modulate the electronic structure of the catalyst,reduce the energy barrier for the oxygen electrode re-action,meanwhile enhance the bifunctional catalytic activity.Impressively,the nickel-cobalt oxide-based LOB with cationic vacancies exhibits large specific capacity(12,205 mAh g^(-1)at 200 mA g^(-1))and good durability.This work provides worthwhile insight into the formation and catalytic enhancement mech-anism of transition metal oxide catalysts with cationic vacancies,and to some extent,the creation of efficient and low-cost oxygen electrocatalysts for LOBs.

Ag doped urchin-like α-MnO2 toward efficient and bifunctional electrocatalysts for Li-02 batteries

Rechargeable Li-O2 batteries (LOBs) have been receiving intensive attention because of their ultra-high theoretical energy densityclose to the gasoline. Herein, Ag modified urchin-like α-MnO2 (Ag-MnO2) material with hierarchical porous structure is obtained bya facile one-step hydrothermal method. Ag-MnO2 possesses thick nanowires and presents hierarchical porous structure of mesoporesand macropores. The unique structure can expose more active sites, and provide continuous pathways for O2 and discharge productsas well. The doping of Ag leads to the change of electronic distribution in α-MnO2 (i.e., more oxygen vacancies), which playimportant roles in improving their intrinsic catalytic activity and conductivity. As a result, LOBs with Ag-MnO2 catalysts exhibit loweroverpotential, higher discharge specific capacity and much better cycle stability compared to pure a-MnO2. LOBs with Ag-MnO2catalysts exhibit a superior discharge specific capacity of 13,131 mA·h·g^-1 at a current density of 200 mA·h·g^-1, a good cycle stabilityof 500 cycles at the capacity of 500 mA·h·g^-1. When current density is increased to 400 mA·h·g^-1, LOBs still retain a long lifespan of170 cycles at a limited capacity of 1,000 mA·h·g^-1.

锂氧电池中基于自支撑Ag/δ-MnO_(2)纳米花正极的可逆LiOH化学

因放电产物对有机电解液具有高攻击性,使得锂-氧电池能量效率低和循环稳定性差的问题一直限制着其实际应用.与典型放电产物过氧化锂相比,氢氧化锂(LiOH)具有更好的化学和电化学稳定性.本文通过在碳纸上原位生长嵌有纳米银的花状二氧化锰作为锂-氧电池的正极(Ag/δ-MnO_(2)@CP),并证明了它能催化LiOH的可逆生成和分解.原位拉曼测试和理论计算表明Ag/δ-MnO_(2)催化放电中间体LiO2*与水分子解离的H+反应最终生成LiOH.以Ag/δ-MnO_(2)@CP为正极的锂-氧电池在潮湿氧气环境下表现出更高的比容量和放电平台.在电流密度为200 mA g^(−1)时,锂-氧电池的过电位仅为0.5 V,在500 mA h g^(−1)的限制比容量下可循环867圈.该工作为研究固相催化剂在锂-氧电池中的作用提供了新的思路,并将促进基于LiOH放电产物的锂-氧电池的实际应用.