More Like this

1. A review on synthesis and engineering of crystal precursors produced via coprecipitation for multicomponent lithium-ion battery cathode materials

   https://doi.org/10.1039/c9ce00679f  

   Dong, Hongxu; Koenig, Gary M. (March 2020, CrystEngComm)

   null (Ed.)

   Interest in developing high performance lithium-ion rechargeable batteries has motivated research in precise control over the composition, phase, and morphology during materials synthesis of battery active material particles for decades. Coprecipitation, as one of the most reported methods in the literature to produce precursors for lithium-ion battery active materials, has drawn attention due to its simplicity, scalability, homogeneous mixing at the atomic scale, and tunability over particle morphology. This highlight summarizes the advancements that have been made in producing crystalline particles of tunable and complex morphologies via coprecipitation for use as lithium-ion battery precursor materials. Comparison among different crystallization reagents, solution conditions that influence the properties of crystal particles, and the fundamental knowledge from equilibrium and/or kinetic study of the coprecipitation processes, are systematically discussed. The research reports and guiding principles summarized in this highlight are meant to improve selections made by researchers to efficiently determine synthesis conditions. In addition, it is desired that the methods applied from the study of crystallization will inspire researchers to pursue further investigation of the nucleation and growth mechanisms of these coprecipitation processes, which will be necessary to achieve truly predictive particle synthesis. 

   more » « less
2. Comparative Analysis of Chemical Redox between Redox Shuttles and a Lithium-Ion Cathode Material via Electrochemical Analysis of Redox Shuttle Conversion

   https://doi.org/10.1149/1945-7111/ac0068  

   Gupta, Devanshi; Cai, Chen; Koenig, Gary M. (May 2021, Journal of The Electrochemical Society)

   Chemical redox reactions between redox shuttles and lithium-ion battery particles have applications in electrochemical systems including redox-mediated flow batteries, photo-assisted lithium-ion batteries, and lithium-ion battery overcharge protection. These previous studies, combined with interest in chemical redox of battery materials in general, has resulted in previous reports of the chemical oxidation and/or reduction of solid lithium-ion materials. However, in many of these reports, a single redox shuttle is the focus and/or the experimental conditions are relatively limited. Herein, a study of chemical redox for a series of redox shuttles reacted with a lithium-ion battery cathode material will be reported. Both oxidation and reduction of the solid material with redox shuttles as a function of time will be probed using ferrocene derivatives with different half-wave potentials. The progression of the chemical redox was tracked by using electrochemical analysis of the redox shuttles in a custom electrochemical cell, and rate constants for chemical redox were extracted from using two different models. This study provides evidence that redox shuttle-particle interactions play a role in the overall reaction rate, and more broadly support that this experimental method dependent on electrochemical analysis can be applied for comparison of redox shuttles reacting with solid electroactive materials. 

   more » « less
3. Analysis of Direct Recycling Methods for Retired Lithium-ion Batteries from Electric Vehicles

   https://doi.org/10.1016/j.procir.2023.02.118  

   Wang, Yu; Zhai, Qiang; Yuan, Chris (January 2023, Procedia CIRP)

   The rapid expansion of electric vehicle (EV) fleet calls for large number of lithium-ion batteries to be recycled at their end-of-life. Various recycling methods have been developed or under development to recover the high-value materials from retired lithium-ion batteries. Amongst these methods, direct recycling techniques have been developed and reported to recycle battery materials for reuse in new battery manufacturing since the electrochemical properties of the recycled materials can be fully recovered to the same level of pristine materials. In literature, innovative sintering processes have been developed to recover the composition and crystal structure of spent cathode materials; hydrothermal regeneration processes have been reported to regenerate the spent cathode materials in the solvents at a moderate temperature, followed by the high-temperature short annealing process. The regenerated cathode materials show the same specific capacity and cycling performance as those of pristine materials. The electrochemical regeneration method is applied to fully recover the electrochemical performance of cathode material with stable crystal structure. While the direct recycling techniques are still under development, their future applications in industry are still not clear. This study aims to classify and summarize state-of-the-art of the direct recycling methods, and evaluate the regenerated cathode materials’ performance and the application potential to be used for manufacturing of new lithium-ion batteries in future. The results will help increase understanding of the direct recycling technologies and facilitate the associated R&D for future industrial scaling-up of direct recycling processes for retired lithium ion batteries from electric vehicles. 

   more » « less
4. Advancements and Challenges in High-Capacity Ni-Rich Cathode Materials for Lithium-Ion Batteries

   https://doi.org/10.3390/ma17040801  

   Ahangari, Mehdi; Szalai, Benedek; Lujan, Josue; Zhou, Meng; Luo, Hongmei (February 2024, Materials)

   Nowadays, lithium-ion batteries are undoubtedly known as the most promising rechargeable batteries. However, these batteries face some big challenges, like not having enough energy and not lasting long enough, that should be addressed. Ternary Ni-rich Li[NixCoyMnz]O2 and Li[NixCoyAlz]O2 cathode materials stand as the ideal candidate for a cathode active material to achieve high capacity and energy density, low manufacturing cost, and high operating voltage. However, capacity gain from Ni enrichment is nullified by the concurrent fast capacity fading because of issues such as gas evolution, microcracks propagation and pulverization, phase transition, electrolyte decomposition, cation mixing, and dissolution of transition metals at high operating voltage, which hinders their commercialization. In order to tackle these problems, researchers conducted many strategies, including elemental doping, surface coating, and particle engineering. This review paper mainly talks about origins of problems and their mechanisms leading to electrochemical performance deterioration for Ni-rich cathode materials and modification approaches to address the problems. 

   more » « less
5. (Digital Presentation) Accelerating the Conversion Process of Polysulfides in High Mass Loading Sulfur Cathode for the Longevity Li-S Battery

   https://doi.org/10.1149/MA2022-012383mtgabs  

   Zhang, Yuxuan; Kivevele, Thomas; Song, Han Wook; Lee, Sunghwan (July 2022, ECS Meeting Abstracts)

   Conventional lithium-ion batteries are unable to meet the increasing demands for high-energy storage systems, because of their limited theoretical capacity. 1 In recent years, intensive attention has been paid to enhancing battery energy storage capability to satisfy the increasing energy demand in modern society and reduce the average energy capacity cost. Among the candidates for next generation high energy storage systems, the lithium sulfur battery is especially attractive because of its high theoretical specific energy (around 2600 W h kg-1) and potential cost reduction. In addition, sulfur is a cost effective and environmentally friendly material due to its abundance and low-toxicity. 2 Despite all of these advantages, the practical application of lithium sulfur batteries to date has been hindered by a series of obstacles, including low active material loading, poor cycle life, and sluggish sulfur conversion kinetics. 3 Achieving high mass loading cathode in the traditional 2D planar thick electrode has been challenged. The high distorsion of the traditional planar thick electrodes for ion/electron transfer leads to the limited utilization of active materials and high resistance, which eventually results in restricted energy density and accelerated electrode failure. 4 Furthermore, of the electrolyte to pores in the cathode and utilization ratio of active materials. Catalysts such as MnO 2 and Co dopants were employed to accelerate the sulfur conversion reaction during the charge and discharge process. 5 However, catalysts based on transition metals suffer from poor electronic conductivity. Other catalysts such as transition metal dopants are also limited due to the increased process complexities. . In addition, the severe shuttle effects in Li-S batteries may lead to fast failures of the battery. Constructing a protection layer on the separator for limiting the transmission of soluble polysulfides is considered an effective way to eliminate the shuttle phenomenon. However, the soluble sulfides still can largely dissolve around the cathode side causing the sluggish reaction condition for sulfur conversion. 5 To mitigate the issues above, herein we demonstrate a novel sulfur electrode design strategy enabled by additive manufacturing and oxidative vapor deposition (oCVD). Specifically, the electrode is strategically designed into a hierarchal hollow structure via stereolithography technique to increase sulfur usage. The active material concentration loaded to the battery cathode is controlled precisely during 3D printing by adjusting the number of printed layers. Owing to its freedom in geometry and structure, the suggested design is expected to improve the Li ions and electron transport rate considerably, and hence, the battery power density. The printed cathode is sintered at 700 °C at N 2 atmosphere to achieve carbonization of the cathode during which intrinsic carbon defects (e.g., pentagon carbon) as catalytic defect sites are in-situ generated on the cathode. The intrinsic carbon defects equipped with adequate electronic conductivity. The sintered 3D cathode is then transferred to the oCVD chamber for depositing a thin PEDOT layer as a protection layer to restrict dissolutions of sulfur compounds in the cathode. Density functional theory calculation reveals the electronic state variance between the structures with and without defects, the structure with defects demonstrates the higher kinetic condition for sulfur conversion. To further identify the favorable reaction dynamic process, the in-situ XRD is used to characterize the transformation between soluble and insoluble polysulfides, which is the main barrier in the charge and discharge process of Li-S batteries. The results show the oCVD coated 3D printed sulfur cathode exhibits a much higher kinetic process for sulfur conversion, which benefits from the highly tailored hierarchal hollow structure and the defects engineering on the cathode. Further, the oCVD coated 3D printed sulfur cathode also demonstrates higher stability during long cycling enabled by the oCVD PEDOT protection layer, which is verified by an absorption energy calculation of polysulfides at PEDOT. Such modeling and analysis help to elucidate the fundamental mechanisms that govern cathode performance and degradation in Li-S batteries. The current study also provides design strategies for the sulfur cathode as well as selection approaches to novel battery systems. References: Bhargav, A., (2020). Lithium-Sulfur Batteries: Attaining the Critical Metrics. Joule 4 , 285-291. Chung, S.-H., (2018). Progress on the Critical Parameters for Lithium–Sulfur Batteries to be Practically Viable. Advanced Functional Materials 28 , 1801188. Peng, H.-J.,(2017). Review on High-Loading and High-Energy Lithium–Sulfur Batteries. Advanced Energy Materials 7 , 1700260. Chu, T., (2021). 3D printing‐enabled advanced electrode architecture design. Carbon Energy 3 , 424-439. Shi, Z., (2021). Defect Engineering for Expediting Li–S Chemistry: Strategies, Mechanisms, and Perspectives. Advanced Energy Materials 11 . Figure 1 

   more » « less