Challenges and new opportunities on barrier performance of biodegradable polymers for sustainable packaging

Electrode processing plays an important role in advancing lithium-ion battery technologies and has a significant impact on cell energy density, manufacturing cost, and throughput. Compared to the extensive research on materials development, however, there has been much less effort in this area. In this Review, we outline each step in the electrode processing of lithium-ion batteries from materials to cell assembly, summarize the recent progress in individual steps, deconvolute the interplays between those steps, discuss the underlying constraints, and share some prospective technologies. This Review aims to provide an overview of the whole process in lithium-ion battery fabrication from powder to cell formation and bridge the gap between academic development and industrial manufacturing.

From Materials to Cell: State-of-the-Art and Prospective Technologies for Lithium-Ion Battery Electrode Processing.

Perovskite-based electronic materials and devices such as perovskite solar cells (PSCs) have notoriously bad reproducibility, which greatly impedes both fundamental understanding of their intrinsic properties and real-world applications. Here, we report that organic iodide perovskite precursors can be oxidized to I2 even for carefully sealed precursor powders or solutions, which markedly deteriorates the performance and reproducibility of PSCs. Adding benzylhydrazine hydrochloride (BHC) as a reductant into degraded precursor solutions can effectively reduce the detrimental I2 back to I−, accompanied by a substantial reduction of I3−-induced charge traps in the films. BHC residuals in perovskite films further stabilize the PSCs under operation conditions. BHC improves the stabilized efficiency of the blade-coated p-i-n structure PSCs to a record value of 23.2% (22.62 ± 0.40% certified by National Renewable Energy Laboratory), and the high-efficiency devices have a very high yield. A stabilized aperture efficiency of 18.2% is also achieved on a 35.8-cm2 mini-module.

https://advances.sciencemag.org/content/advances/7/10/eabe8130.full.pdf

Iodine reduction for reproducible and high-performance perovskite solar cells and modules.

In this work, we report perovskite solar cells in the planar p–i–n configuration based on single-step, anti-solvent-free, low-temperature (70 °C) slot-die-coated methylammonium lead tri-iodide (MAP...

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High-Performance Perovskite Single-Junction and Textured Perovskite/Silicon Tandem Solar Cells via Slot-Die-Coating

Challenges in fabricating all-perovskite tandem solar cells as modules rather than as single-junction configurations include growing high-quality wide-bandgap perovskites and mitigating irreversible degradation caused by halide and metal interdiffusion at the interconnecting contacts. We demonstrate efficient all-perovskite tandem solar modules using scalable fabrication techniques. By systematically tuning the cesium ratio of a methylammonium-free 1.8–electron volt mixed-halide perovskite, we improve the homogeneity of crystallization for blade-coated films over large areas. An electrically conductive conformal “diffusion barrier” is introduced between interconnecting subcells to improve the power conversion efficiency (PCE) and stability of all-perovskite tandem solar modules. Our tandem modules achieve a certified PCE of 21.7% with an aperture area of 20 square centimeters and retain 75% of their initial efficiency after 500 hours of continuous operation under simulated 1-sun illumination. Description Large-area tandem perovskite solar cells Tandem solar cells allow more of the solar spectrum to be used. For all-perovskite implementations with large illumination areas, different bad-gap compositions must be grown with fully scalable methods. Xiao et al. blade coated high-quality, wide-bandgap perovskite layers by tuning the cesium concentration in a mixed solvent system. They avoided diffusion between the perovskite layers with a tin oxide layer grown by atomic layer deposition that also served as an electron extractor. Small-area cells (1 square centimeter) have a power conversion efficiency (PCE) of about 25%, and a 20-square-centimeter module had a certified PCE of 21.7%. The encapsulated tandem module maintained more than 75% of its initial PCE after maximum power point operation for over 500 hours in ambient air. —PDS Improved crystallization enables all-perovskite, large-area tandem solar module fabrication with fully scalable processing.

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Scalable processing for realizing 21.7%-efficient all-perovskite tandem solar modules

To make perovskite solar cells an industrially relevant technology large area deposition techniques are needed and one of the most promising is slot-die coating. This review article details the progress reported in the literature where slot-die coating has been used for the deposition of both the perovskite layer and other layers in the perovskite solar cell device stack. An overview of the methods used to adapt the coating process, materials and drying conditions in order to create high quality layers and devices is given and an outlook on future research directions in this field is made.

https://cronfa.swan.ac.uk/Record/cronfa52964/Download/52964__16040__f0edea3933a14d3aa6995029c18d157a.pdf

Slot-die coating of perovskite solar cells: An overview

Roll-to-roll coating of all active layers is demonstrated for a P–I–N perovskite solar cell stack, using a single step perovskite ink with an acetonitrile solvent system and flexible plastic substrate. A slot-die coating roll-to-roll process (with a common coating speed for all layers) is developed by using appropriate length meniscus guides as part of the coating head for each ink rheology. High performance devices are demonstrated with four roll-to-roll slot-die coated layers and evaporated top electrode. The drying conditions of the perovskite layer are optimized and found to be critical to achieving good performance. Multi solvent blend systems for the electron collection layer are developed that are more industrially compatible than the commonly used chlorobenzene solvent system and make use of a gradient of solvent volatilities to give both good macro film formation and rapid drying. A stabilised power conversion efficiency of 12.2% is demonstrated, that is the highest reported to date for devices with all layers other than the top electrode deposited roll-to-roll. This work demonstrates the feasibility of a roll-to-roll fabrication process for perovskite solar cells that could be transferred to a fully inline roll-to-roll process with all coating and drying stages made sequentially on one line running at a common coating speed and further demonstrates the potential to produce high efficiency photovoltaics using roll-to-roll fabrication methods.

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Roll-to-roll slot-die coated P–I–N perovskite solar cells using acetonitrile based single step perovskite solvent system

https://pubs.rsc.org/en/content/articlepdf/2021/gc/d1gc00079a

Sustainable solvent selection for the manufacture of methylammonium lead triiodide (MAPbI3) perovskite solar cells

This manuscript introduces solvent toxicity in solar perovskite ink chemistries as a major technoeconomic limitation for the growth of the technology. More specifically, the capital and operational cost of handling such toxic chemicals to maintain a safe working environment can lead to significant added costs. As all record power conversion efficiency devices to date have been solution processed, this represents a major challenge for the perovskite optoelectronic field and of printed electronics as a whole. Knowing this limitation, we propose that solvent selections for ink chemistries should be more quantitative and focus on lowering toxicity. To this end, we show that a Hansen solubility model is effective in predicting ink systems using lower toxicity solvents. We also show that inks formed from this method are applicable for high-speed slot-die coating, limiting the need for long anneal times. These methods and results demonstrate a useful framework for quantitatively engineering solvent systems with reduced toxicity while simultaneously maintaining and surpassing performance. It therefore provides a pathway and major step forward towards the commercialization of solution coated perovskite technologies.

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Predicting Low Toxicity and Scalable Solvent Systems for High-Speed Roll-to-Roll Perovskite Manufacturing

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Rahul Patidar

Papers

Slot-die coating of perovskite solar cells: An overview

Roll-to-roll slot-die coated P–I–N perovskite solar cells using acetonitrile based single step perovskite solvent system

Sustainable solvent selection for the manufacture of methylammonium lead triiodide (MAPbI3) perovskite solar cells

Predicting Low Toxicity and Scalable Solvent Systems for High-Speed Roll-to-Roll Perovskite Manufacturing

Development of roll-to-roll slot die coated perovskite solar cells