METHODS OF CHEMICAL SEPARATION USING SELECTIVE AND SEQUENTIAL PRECIPITATION IN REACTION-DIFFUSION GEL MEDIA (iEdison No. 0685901-23-0116)
We developed a strategy based on reaction-diffusion coupling to achieve selective precipitation from a multicomponent feedstock solution. As proof-of-concept, we demonstrated this approach for a solution of mixed metal salts, namely Mn-Co-Ni chlorides; an important problem in the context of critical materials recovery from recycled electrodes. The solution mixture is placed in a cylinder on top of an agarose hydrogel layer loaded with reacting counterions, in this case sodium hydroxide (Figure 1). As the metal ions diffuse into the gel, crystallization begins to take place in regions of high supersaturation, which locally depletes the ions, to be subsequently replenished by diffusive flux. This interplay of diffusion, nucleation, and growth kinetics results in a spatial unfolding of unique nonequilibrium conditions along the length of the reactor. We observe that the chemical composition of the precipitates showed a gradient along the length of the reactor, ultimately producing almost pure manganese (hydr)oxide beyond a sharp boundary of other mixed phases (Figure 3, unpublished). Note that this separation was accomplished without the use of complex membranes, binding agents, high temperature processing, or even electric fields. The metal ion mixture was simply placed on top of a hydrogel loaded with sodium hydroxide and allowed to 'develop" such that the various metal oxides were formed in order of their precipitation rates as they diffuse into the gel.
ZINC-IODINE SECONDARY ENERGY STORAGE METHODS, DEVICES, AND ELECTRLYTES
Disclosed are cathodes having electron-conductive high-surface-area materials, aqueous non-halide-containing electrolytes, secondary zinc-iodine energy storage devices using the same, and methods for assembling the same. The disclosed high-surface-area materials and the aqueous non-halide-containing electrolyte solutions can contribute together to the confinement of the active iodine species in the cathode and to the minimization of shuttle effects and self-discharging. The non-halide-containing electrolyte salts can facilitate preferential adsorption of the iodine species to the cathode material rather than dissolution in the aqueous electrolyte solution, thereby contributing to the confinement of the active iodine species.
IRON COMPLEXES WITH PHOSPHONATE-BASED LIGANDS AS RFB ANOLYTE MATERIALS (iEdison No. iEdison No. 0685901-21-0132)
The present invention reports iron complexes based on multidentate ligands with phosphonate coordination groups. These metal complexes are used as anolyte materials in aqueous redox flow batteries. Proposed all soluble iron flow batteries have a battery structure similar to conventional RFB technology, which consists of an anolyte tank and a catholyte tank, and a flow battery stack. Compared with the vanadium redox flow battery (VRFB), the main advantage achieved by the present invention is the use of a cost-effective iron complex-based electrolyte to replace the high-cost vanadium electrolyte, thereby further reducing the cost of RFB technology.
ADDITIVES FOR FLUORENONE/FLUORENOL BASED AQUEOUS REDOX FLOW BATTERIES (iEdison No. 0685901-21-0130)
In this invention disclose report, hydroxyl compound additives are disclosed as significantly improve the kinetics of the FL (fluorenone)-based aqueous redox flow battery (ARFB) (Selected examples of hydroxyl compounds and examples of molecular engineered FLs tested as illustrated in Supporting Figure 1). Application of FL derivatives in flow battery has been reported in nonaqueous systems and aqueous systems. Higher energy density and power density are always the pursuits during RFB redox-active material development. For a certain redox pair applied in RFB, capacity utilization usually decreases while current density increases due to the kinetics limit. It is of keen interest to maintaining battery discharge capacity at elevated current density, thus achieving long-time operation and high-power output at the same time. Here we disclose hydroxyl compound can serve as additives for FL-based ARFBs to significantly improve their rate capability and power output. To our best knowledge, this is a first-time demonstration of the utilization of additives to boost rate capability in RFBs. The development of this approach will have a revolutionary impact. In our examination, selected examples of molecular engineered FLs benefited from 0.1 M beta CD additive, demonstrating significant discharge capacity enhancement at higher current densities when comparing with a blank test. A case study using 27S4CFL extended the additive ranges to other hydroxyl-containing redox-inert compounds. Cyclic Voltammetry (CV) scans of these additives revealed no redox peak within the water window in alkaline conditions. Conductivity and viscosity both exhibited a negative effect on the battery performance while the overall current density was boosted by adding in these additives. An observation that is contrary to common understanding of those skilled in the field of energy storage and electrochemistry. The additive concentration effect was investigated using beta CD, the result showed a peak battery performance when 0.086 M beta CD was employed in the system. The long-term battery operation revealed a minimal effect on the battery cycling stability.
IN-SITU HEALTH MONITORING SYSTEM FOR REDOX FLOW BATTERIES (iEdison No. 0685901-22-0242)
We designed an acoustic monitoring system to detect hydrogen bubbles in the analyte solution of all-vanadium redox flow batteries (AVFBs). The system has a specially designed ultrasonic probing cell made of borosilicate glass that can be integrated into the flow system on the analyte side (Figure 1). The analyte solution firstly flows through the negative electrode, where the chemical reaction occurs and hydrogen bubbles are generated, and then flows into the ultrasonic probing cell. The ultrasonic transducer transmits signals into the probing cell and collects echoes that propagate through the electrolyte solution in the probing cell. Details about how the signals are transmitted and received are included in Appendix A. The echoes are collected by the ultrasonic receiver and sent to the computer for data analysis. The sound speed and the acoustic attenuation coefficient are calculated from these echoes, with the detailed methods given in Appendix B and C. Bubbles that flow through the acoustic path are reflected as abnormal values in the measurements of the sound speed and the attenuation coefficient. This method not only can detect bubbles in the analyte solution, but also can estimate the bubble flow speed. The monitoring system can continuously monitor bubble amounts in negative electrolytes without interrupting the battery operation, and thus provides a real-time noninvasive surveillance of the health status of flow battery systems. Figure 1. Schematic of the in-situ battery health monitoring system for hydrogen detection in an all-vanadium redox flow battery.
GIBS: A Grand Canonical Monte Carlo simulation program for computing ion distributions around biomolecules in hard sphere solvents.
The GIBS software program is a Grand Canonical Monte Carlo (GCMC) simulation program (written in C++) that can be used for 1) computing the excess chemical potential of ions and the mean activity coefficients of salts in homogeneous electrolyte solutions; and, 2) for computing the distribution of ions around fixed macromolecules such as, nucleic acids and proteins. The solvent can be represented as neutral hard spheres or as a dielectric continuum. The ions are represented as charged hard spheres that can interact via Coulomb, hard-sphere, or Lennard-Jones potentials. In addition to hard-sphere repulsions, the ions can also be made to interact with the solvent hard spheres via short-ranged attractive square-well potentials. In GIBS, the excess chemical potential of ions is computed using the adaptive iterative GCMC algorithm developed by Malasics and Boda (Journal of Chemical Physics, 132, 2010). The standard Metropolis algorithm is used to sample the distribution of ions, which determines the acceptance rates for inserting, deleting, and displacing an ion at each simulation step. The site for inserting an ion is randomly selected based on a cavity-biased, grid-insertion algorithm developed by Woo et al (Journal of Chemical Physics, 121, 2004). GIBS can handle systems of different ion sizes, and implements an efficient algorithm to track the list of cavities available for each particle type(ion and solvent hard spheres) after every single-particle insertion/deletion/displacement, and to quickly sample this list and select the site for inserting a particle. The GIBS program was written by Dr. Dennis G. Thomas in collaboration with Dr. Nathan A. Baker, at Pacific Northwest National Laboratory. The program was developed as part of projects funded by the National Institutes of Health through R01 Grant Nos. GM076121-04S1 and GM099450.
Localized High Concentration Electrolytes for Stable Cycling of Electrochemical Devices
DIRECT RECYCLING AND CONVERTING CATHODE MATERIALS INTO HIGH-PERFORMANCE SINGLE CRYSTAL CATHODE MATERIALS (iEdison No. 0685901-22-0122)
A cost-effective approach is disclosed in this invention to converting recycled LiNixMnyCozO2 (referred to as NMC hereafter, x+y+z=1), regardless of the stoichiometry of Ni,Mn,Co and morphologies of different NMC used in various batteries, into high performance single crystal Ni-rich NMC such as LiNi0.8Mn0.1Co0.1O2 with simple heating process with Li2O (background IP: Cost effective synthesis of oxide materials for lithium ion batteries, US20220112094A1). The reported approach significantly simplifies the synthesis process of NMC by using recycled cathode materials which not only reduces manufacturing cost but supports a stable domestic supply chain. In addition, the different NMC cathodes recycled from various batteries are directly converted into single crystal Ni-rich NMC which is critical for large-scale deployment of Ni-rich NMC for current and future Li-based battery technologies. This invention is well aligned with the recent DOE FOA (DE-FOA-0002680) which focuses on battery recycling. Expedient filing of this invention will enable PNNL engagement with industry.
Arun Devaraj, PhD, Materials Scientist
Long-Duration Energy Storage Can’t Wait
Long-duration energy storage gets the spotlight in a new Energy Storage Research Alliance featuring PNNL innovations, like a molecular digital twin and advanced instrumentation.