the main concern for degrading the device stability; for example, CH 3 NH 3 PbI 3 could be decomposed into lead Iodide (PbI 2 ) and CH 3 NH 3 I, and the organic molecules could be vapored under thermal or humidity environment. [15] Therefore, addressing the long-term stability is a primary concern for the perovskite solar cells community. [16] As an alternative, all-inorganic perovskites (CsPbX 3 , X = I, Br, Cl, or their mixtures), prized for their excellent thermal stability, have received increasing attention. [17][18][19][20][21][22][23] Among them CsPbI 3-x Br x with the band gap of around 1.73 eV showed promising, by stabilizing the α-phase, control growth of the perovskite layer, and also the interface engineering, significant progresses have been achieved. For example, Luther et al. have shown CsPbI 3 quantum dot solar cells with the efficiency of 10.77% and 13.4%, subsequently. [24,25] Our group has developed a solvent controlled growth of CsPbI 3 in dry environment, and showed a 14.67% certificated efficiency with 500 h light-soaking stability. [26] Li et al. invented a novel gradient thermal annealing to control the growth of CsPbI 2 Br film (band gap = 1.92 eV), and a champion PCE of 16.07% with a V OC of 1.23 V was realized. [27] Recently, an outstanding efficiency of 17.06% with V OC of 1.1 V was realized by Zhao et al. via using HPbI 3 as a precursor combined with the PTABr surface modification. [28] Although there are significant progresses in inorganic perovskite solar cells, the PCE is still far behind the hybrid PSCs, even compared with the I-Br mixed hybrid perovskite with a similar band gap (1.75 eV). [29] It can be found that the opencircuit voltage loss (V oc loss) is still the main reason of low performance of inorganic perovskite solar cells, which strongly related to energy band matching and defects at the interface or in the bulk of perovskite. [10,14] Most recently, Yip et al. applied PN4N as cathode interlayer to reduce the work function of the SnO 2 electron transporting layer (ETL) for tuning the electron extraction property and combing with poly[5,5′-bis(2-butyloctyl)-(2,2′-bithiophene)-4,4′-dicarboxylate-alt-5,5′-2,2′-bithiophene] (PDCBT) as hole transporting layer, leading to a significant enhancement in V OC of the CsPbI 3-x Br x PVSCs from 1.06 to 1.3 V [30] ; however, the V oc loss is still as high as 0.62 V .Here, we develop an inorganic shunt-blocking layer lithium fluoride (LiF) between SnO 2 and CsPbI 3-x Br x perovskites, which push forward the conduction band of the electron transport Cesium-based inorganic perovskite solar cells (PSCs) are promising due to their potential for improving device stability. However, the power conversion efficiency of the inorganic PSCs is still low compared with the hybrid PSCs due to the large open-circuit voltage (V OC ) loss possibly caused by charge recombination. The use of an insulated shunt-blocking layer lithium fluoride on electron transport layer SnO 2 for better energy level alignment with the conduction band minimum of the CsPbI...

involved, and affordable cost. [1][2][3] However, the commercial application of the sulfur cathode for the Li-S batteries is restrained by several technical barriers [4][5][6] compared with Li-ion battery. [7] First, the poor conductivity of sulfur and its reaction intermediates limit the sulfur utilization, [8] which leads to decreased energy density and power density. Second, during the charge/discharge process, there is a large volume change, resulting in rapid deterioration of the electrode structure. Various strategies have been investigated to increase electrode conductivity and to accommodate the volume expansion. [9][10][11] Last but not least, the dissolution and transport of lithium polysulfides (LiPSs) in the electrolyte result in the fatal "shuttle effect" that causes the deposition of Li 2 S on Li anode and then degrades the cycle performance. This shuttle effect could be mitigated by 1) trapping/confining the soluble LiPSs in the cathode by physical and chemical adsorption, [12][13][14][15] which prevents the transport of soluble LiPSs in the electrolyte, and 2) enhancing the kinetics of LiPS conversion reactions so that the soluble long-chain LiPS could transform to insoluble short-chain LiPS quickly, limiting the lifetime of soluble LiPS. [16,17] Therefore, a superior Li-S battery could be achieved by designing a cathode with high electricalThe lithium-sulfur (Li-S) battery is widely regarded as a promising energy storage device due to its low price and the high earth-abundance of the materials employed. However, the shuttle effect of lithium polysulfides (LiPSs) and sluggish redox conversion result in inefficient sulfur utilization, low power density, and rapid electrode deterioration. Herein, these challenges are addressed with two strategies 1) increasing LiPS conversion kinetics through catalysis, and 2) alleviating the shuttle effect by enhanced trapping and adsorption of LiPSs. These improvements are achieved by constructing double-shelled hollow nanocages decorated with a cobalt nitride catalyst. The N-doped hollow inner carbon shell not only serves as a physiochemical absorber for LiPSs, but also improves the electrical conductivity of the electrode; significantly suppressing shuttle effect. Cobalt nitride (Co 4 N) nanoparticles, embedded in nitrogen-doped carbon in the outer shell, catalyze the conversion of LiPSs, leading to decreased polarization and fast kinetics during cycling. Theoretical study of the Li intercalation energetics confirms the improved catalytic activity of the Co 4 N compared to metallic Co catalyst. Altogether, the electrode shows large reversible capacity (1242 mAh g −1 at 0.1 C), robust stability (capacity retention of 658 mAh g −1 at 5 C after 400 cycles), and superior cycling stability at high sulfur loading (4.5 mg cm −2 ).

Despite the tremendous progress of coupling organic electrooxidation with hydrogen generation in a hybrid electrolysis, electroreforming of raw biomass coupled to green hydrogen generation has not been reported yet due to the rigid polymeric structures of raw biomass. Herein, we electrooxidize the most abundant natural amino biopolymer chitin to acetate with over 90% yield in hybrid electrolysis. The overall energy consumption of electrolysis can be reduced by 15% due to the thermodynamically and kinetically more favorable chitin oxidation over water oxidation. In obvious contrast to small organics as the anodic reactant, the abundance of chitin endows the new oxidation reaction excellent scalability. A solar-driven electroreforming of chitin and chitin-containing shrimp shell waste is coupled to safe green hydrogen production thanks to the liquid anodic product and suppression of oxygen evolution. Our work thus demonstrates a scalable and safe process for resource upcycling and green hydrogen production for a sustainable energy future.

In the past ten years, organic-inorganic hybrid perovskite solar cells have achieved great progress, the power conversion efficiency (PCE) grew from 3.8 to 25.2%, which is comparable with the best thin-film chalcogenide and silicon devices. [1-11] Unfortunately, the poor thermal stability and moisture sensitivity caused by the weak hydrogen-bonding between organic cation and octahedral PbI 2 make a huge obstacle in the way Cesium lead iodide (CsPbI 3) perovskite has gained great attention due to its potential thermal stability and appropriate bandgap (≈1.73 eV) for tandem cells. However, the moisture-induced thermodynamically unstable phase and large open-circuit voltage (V OC) deficit and also the low efficiency seriously limit its further development. Herein, long chain phenylethylammonium (PEA) is utilized into CsPbI 3 perovskite to stabilize the orthorhombic black perovskite phase (γ-CsPbI 3) under ambient condition. Furthermore, the moderate lead acetate (Pb(OAc) 2) is controlled to combine with phenylethylammonium iodide to form the 2D perovskite, which can dramatically suppress the charge recombination in CsPbI 3. Unprecedentedly, the resulted CsPbI 3 solar cells achieve a 17% power conversion efficiency with a record V OC of 1.33 V, the V OC deficit is only 0.38 V, which is close to those in organic-inorganic perovskite solar cells (PSCs). Meanwhile, the PEA modified device maintains 94% of its initial efficiency after exceeding 2000 h of storage in the low-humidity controlled environment without encapsulation. of their commercialization. [12-13] Recently, cesium lead halide perovskite absorbers through substituting the organic cation by inorganic Cs + are heavily favored due to their potential in improving stability. [14-16] Nevertheless, the desired black phase CsPbI 3 is moisture-induced thermodynamically unstable, which spontaneously transforms into an unfavorable yellow phase with non-perovskite structure. [17-19] Many strategies have been extensively explored to stabilize the black phase of CsPbI 3 including HI additive, [20,21] transition element doping, [22-29] alloys with Br, [30-33] or using quantum dots, [34,35] but unfortunately, the incorporation of Br and quantum dots effect will inevitably widen the perovskite bandgap sacrificing the efficiency. Most recently, long chain organic ligands such as polyvinylpyrrolidone (PVP), phenylethylamine (PEA) were demonstrated to be effective in improving the moisture stability of CsPbI 3. [36,37] However, the efficiency of these solar cells is far behind the current progress in inorganic solar cells with the PCE exceeding 17% mainly due to the deficiency on open-circuit voltage (V OC) caused by charge recombination in the bulk or the interface. [30,38-40] It is worth mentioning that introducing 2D/3D perovskite configuration into perovskite can improve the device performance by surface or bulk passivation for reducing the V OC deficits. By introducing a small amount of 2D EDAPbI 4 into perovskite precursor, Zhao et al. fabricated the perovskite device wi...