Barrier Designs in Perovskite Solar Cells for Long‐Term Stability

Perovskite solar cells (PSCs) have attracted much attention in the past decade and their power conversion efficiency has been rapidly increasing to 25.2%, which is comparable with commercialized solar cells. Currently, the long‐term stability of PSCs remains as a major bottleneck impeding their future commercial applications. Beyond strengthening the perovskite layer itself and developing robust external device encapsulation/packaging technology, integration of effective barriers into PSCs has been recognized to be of equal importance to improve the whole device’s long‐term stability. These barriers can not only shield the critical perovskite layer and other functional layers from external detrimental factors such as heat, light, and H₂O/O₂, but also prevent the undesired ion/molecular diffusion/volatilization from perovskite. In addition, some delicate barrier designs can simultaneously improve the efficiency and stability. In this review article, the research progress on barrier designs in PSCs for improving their long‐term stability is reviewed in terms of the barrier functions, locations in PSCs, and material characteristics. Regarding specific barriers, their preparation methods, chemical/photoelectronic/mechanical properties, and their role in device stability, are further discussed. On the basis of these accumulative efforts, predictions for the further development of effective barriers in PSCs are provided at the end of this review.     

Ultrafine Co3Se4 Nanoparticles in Nitrogen‐Doped 3D Carbon Matrix for High‐Stable and Long‐Cycle‐Life Lithium Sulfur Batteries

Lithium–sulfur batteries are a promising high energy output solution for substitution of traditional lithium ion batteries. In recent times research in this field has stepped into the exploration of practical applications. However, their applications are impeded by cycling stability and short life‐span mainly due to the notorious polysulfide shuttle effect. In this work, a multifunctional sulfur host fabricated by grafting highly conductive Co₃Se₄ nanoparticles onto the surface of an N‐doped 3D carbon matrix to inhibit the polysulfide shuttle and improve the sulfur utilization is proposed. By regulating the carbon matrix and the Co₃Se₄ distribution, N‐CN‐750@Co₃Se₄‐0.1 m with abundant polar sites is experimentally and theoretically shown to be a good LiPSs absorbent and a sulfur conversion accelerator. The S/N‐CN‐750@Co₃Se₄‐0.1 m cathode shows excellent sulfur utilization, rate performance, and cyclic durability. A prolonged cycling test of the as‐fabricated S/N‐CN‐750@Co₃Se₄‐0.1 m cathode is carried out at 0.2 C for more than 5 months which delivers a high initial capacity of 1150.3 mAh g^?1 and retains 531.0 mAh g^?1 after 800 cycles with an ultralow capacity reduction of 0.067% per cycle, maintaining Coulombic efficiency of more than 99.3%. The reaction details are characterized and analyzed by ex situ measurements. This work highly emphasizes the potential capabilities of transition‐metal selenides in lithium–sulfur batteries.     

A Review on Additives for Halide Perovskite Solar Cells

Additives are widely adopted for efficient, stable, and hysteresis‐free perovskite solar cells and play an important role in various breakthroughs of perovskite solar cells (PSCs). Herein the various additives adopted for PSCs are reviewed and their functioning mechanism and influence on device performance is described. The main roles of additives, modulating morphology of perovskite films, stabilizing phase of formamidinium (FA) and cesium (Cs)‐based perovskites, adjusting energy level alignment in PSCs, suppressing nonradiative recombination in perovskites, eliminating hysteresis, enhancing operational stability of PSCs, are summarized.     

Promises of Main Group Metal–Based Nanostructured Materials for Electrochemical CO2 Reduction to Formate

Selective CO₂ reduction to formic acid or formate is the most technologically and economically viable approach to realize electrochemical CO₂ valorization. Main group metal–based (Sn, Bi, In, Pb, and Sb) nanostructured materials hold great promise, but are still confronted with several challenges. Here, the current status, challenges, and future opportunities of main group metal–based nanostructured materials for electrochemical CO₂ reduction to formate are reviewed. Firstly, the fundamentals of electrochemical CO₂ reduction are presented, including the technoeconomic viability of different products, possible reaction pathways, standard experimental procedure, and performance figures of merit. This is then followed by detailed discussions about different types of main group metal–based electrocatalyst materials, with an emphasis on underlying material design principles for promoting the reaction activity, selectivity, and stability. Subsequently, recent efforts on flow cells and membrane electrode assembly cells are reviewed so as to promote the current density as well as mechanistic studies using in situ characterization techniques. To conclude a short perspective is offered about the future opportunities and directions of this exciting field.     

New Lithium Salt Forms Interphases Suppressing Both Li Dendrite and Polysulfide Shuttling

Lithium–sulfur batteries (LSBs) are considered promising candidates for the next‐generation energy‐storage systems due to their high theoretical capacity and prevalent abundance of sulfur. Their reversible operation, however, encounters challenges from both the anode, where dendritic and dead Li‐metal form, and the cathode, where polysulfides dissolve and become parasitic shuttles. Both issues arise from the imperfection of interphases between electrolyte and electrode. Herein, a new lithium salt based on an imide anion with fluorination and unsaturation in its structure is reported, whose interphasial chemistries resolve these issues simultaneously. Lithium 1, 1, 2, 2, 3, 3‐hexafluoropropane‐1, 3‐disulfonimide (LiHFDF) forms highly fluorinated interphases at both anode and cathode surfaces, which effectively suppress formation of Li‐dendrites and dissolution/shuttling of polysulfides, and significantly improves the electrochemical reversibility of LSBs. In a broader context, this new Li salt offers a new perspective for diversified beyond Li‐ion chemistries that rely on a Li‐metal anode and active cathode materials.     

人免疫球蛋白联合IMP/CS和PS/TS对重症肺部感染患者炎性因子及T细胞亚群的影响

目的:人免疫球蛋白(HIG)联合亚胺培南西司他丁钠(IMP/CS)和哌拉西林他唑巴坦钠(PS/TS)治疗重症肺部感染的临床疗效。方法:选择2013年3月～2018年7月复旦大学附属华山医院北院收治的重症肺部感染患者99例为研究对象,采用随机数字法分为A组(33例,采用HIG+IMP/CS+PS/TS治疗)、B组(33例,采用IMP/CS+PS/TS治疗)和C组(33例,采用PS/TS治疗),比较三组有效率、炎性因子、T细胞亚群和不良反应。结果:A组临床总有效率为96.97%,高于B组的78.79%,B组高于C组的60.61%(P0.05)。治疗7 d后,三组C反应蛋白(CRP)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、CD8~+水平较治疗前降低,CD4~+和CD4~+/CD8~+较治疗前升高,差异有统计学意义(P0.05)。治疗7 d后,A组CRP、IL-6、TNF-α、CD8~+水平低于B组,B组低于C组(P0.05);治疗7d后,A组CD4~+和CD4~+/CD8~+高于B组,B组高于C组(P0.05)。三组治疗期间均无药物相关不良反应的发生。结论:HIG联合IMP/CS和PS/TS治疗重症肺部感染患者安全有效,能有效改善患者的炎性反应,调节免疫功能,促进患者恢复。     

Shortened snRNA promoters for efficient CRISPR/Cas-based multiplex genome editing in monocot plants

正Dear Editor,CRISPR (clustered regularly interspaced short palindromic repeats)/Cas genome editing is a powerful tool for introducing specific mutations in organisms including plants. The system is composed of a nuclease such as Cas9 or Cas12a and an engineered single-guide RNA (sgRNA) incorporating a target sequence (Li et al., 2019). A Cas9/sgRNA complex re-     

Loci and candidate gene identification for soybean resistance to Phytophthora root rot race 1 in combination with association and linkage mapping

Molecular Breeding - Northern corn leaf blight (NCLB) is one of the main diseases of maize, which greatly reduces production and causes millions of dollars in losses worldwide annually....