GREENLION Project: Advanced Manufacturing Processes for Low Cost Greener Li-Ion Batteries

GREENLION is a Large Scale Collaborative Project within the FP7 (GC.NMP.2011-1) leading to the manufacturing of greener and cheaper Li-Ion batteries for electric vehicle applications via the use of water soluble, fluorine-free, high thermally stable binders, which would eliminate the use of VOCs and reduce the cell assembly cost. The project has 6 key objectives: (i) development of new active and inactive battery materials viable for water processes (green chemistry); (ii) development of innovative processes (coating from aqueous slurries) capable of reducing electrode production cost and avoid environmental pollution; (iii) development of new assembly procedures (including laser cutting and high temperature pre-treatment) capable of substantially reduce the time and the cost of cell fabrication; (iv) lighter battery modules with easier disassembly through eco-designed bonding techniques; (v) waste reduction, which, by making use of the watersolubility of the binder, allows the extensive recovery of the active and inactive battery materials; and (vi) development of automated process and construction of fully integrated battery module for electric vehicle applications with optimized electrodes, cells, and other ancillaries. Achievements during the first 18 months of the project, especially on materials development and water-based electrode fabri cation are reported herein

Core-shell tin oxide, indium oxide, and indium tin oxide nanoparticles on Si with tunable dispersion: Electrochemical and structural characteristics as a hybrid Li-ion battery anode

Tin oxide (SnO2) is considered a very promising material as a high capacity Li-ion battery anode. Its adoption depends on a solid understanding of factors that affect electrochemical behavior and performance such as size and composition. We demonstrate here, that defined dispersions and structures can improve our understanding of Li-ion battery anode material architecture on alloying and co-intercalation processes of Lithium with Sn from SnO2 on Si. Two different types of well-defined hierarchical Sn@SnO2 core–shell nanoparticle (NP) dispersions were prepared by molecular beam epitaxy (MBE) on silicon, composed of either amorphous or polycrystalline SnO2 shells. In2O3 and Sn doped In2O3 (ITO) NP dispersions are also demonstrated from MBE NP growth. Lithium alloying with the reduced form of the NPs and co-insertion into the silicon substrate showed reversible charge storage. Through correlation of electrochemical and structural characteristics of the anodes, we detail the link between the composition, areal and volumetric densities, and the effect of electrochemical alloying of Lithium with Sn@SnO2 and related NPs on their structure and, importantly, their dispersion on the electrode. The dispersion also dictates the degree of co-insertion into the Si current collector, which can act as a buffer. The compositional and structural engineering of SnO2 and related materials using highly defined MBE growth as model system allows a detailed examination of the influence of material dispersion or nanoarchitecture on the electrochemical performance of active electrodes and materials

Rechargeable Li-ion battery anode of indium oxide with visible to infra-red transparency

Unique bimodal distributions of single crystal epitaxially grown In2O3 nanodots on silicon are shown to have excellent IR transparency greater than 87% at 4 μm without sacrificing transparency in the visible region. These broadband antireflective nanodot dispersions are grown using a two-step metal deposition and oxidation by molecular beam epitaxy, and backscattered diffraction confirms a dominant (111) surface orientation. We detail the growth of a bimodal size distribution that facilitates good surface coverage (80%) while allowing a significant reduction in In2O3 refractive index. The (111) surface orientation of the nanodots, when fully ripened, allows minimum lattice mismatch strain between the In2O3 and the Si surface. This helps to circumvent potential interfacial weakening caused by volume contraction due to electrochemical reduction to lithium, or expansion during lithiation. Cycling under potentiodynamic conditions shows that the transparent anode of nanodots reversibly alloys lithium with good Coulombic efficiency, buffered by co-insertion into the silicon substrate. These properties could potentially lead to further development of similarly controlled dispersions of a range of other active materials to give transparent battery electrodes or materials capable of non-destructive in-situ spectroscopic characterization during charging and discharging

2023 roadmap for potassium-ion batteries

The heavy reliance of lithium-ion batteries (LIBs) has caused rising concerns on the sustainability of lithium and transition metal and the ethic issue around mining practice. Developing alternative energy storage technologies beyond lithium has become a prominent slice of global energy research portfolio. The alternative technologies play a vital role in shaping the future landscape of energy storage, from electrified mobility to the efficient utilization of renewable energies and further to large-scale stationary energy storage. Potassium-ion batteries (PIBs) are a promising alternative given its chemical and economic benefits, making a strong competitor to LIBs and sodium-ion batteries for different applications. However, many are unknown regarding potassium storage processes in materials and how it differs from lithium and sodium and understanding of solid–liquid interfacial chemistry is massively insufficient in PIBs. Therefore, there remain outstanding issues to advance the commercial prospects of the PIB technology. This Roadmap highlights the up-to-date scientific and technological advances and the insights into solving challenging issues to accelerate the development of PIBs. We hope this Roadmap aids the wider PIB research community and provides a cross-referencing to other beyond lithium energy storage technologies in the fast-pacing research landscape

Nano-structuring of silicon and germanium :a viable route to high capacity, long cycle life lithium-ion battery electrodes

This thesis describes the development of high-capacity, next generation Li-ion battery electrodes based on germanium and silicon nanostructures grown directly from stainless steel current collectors. The core chapters are arranged as research articles with introductory summaries at the beginning of each. The anode component of current commercial Li-ion batteries is typically composed of graphite (theoretical capacity of 372 mAhg-1); even though, Ge and Si anodes boast multiples of this due to their ability to form lithium rich alloys. However, the formation of these high capacity lithiated alloys, Li15Ge4 (1384 mAhg-1) and Li15Si4 (3579 mAhg-1), leads to considerable expansion of bulk Ge and Si electrodes (> 300%) which causes pulverisation of the material and loss of contact with the current collector, ultimately limiting the cycle life of Li-alloying anodes. Nanowire based electrodes overcome this as they circumvent the pulverisation issue due to the unique properties bestowed upon them by their nano-dimensions. Chapter 3 describes the development of Sn seeded Ge NW electrodes that retain very high capacities of 900 mahg-1 after 1100 cycles and also display excellent rate performance characteristics. Conventional wisdom in the field is that nanowire based materials outperform their bulk counterparts as the smaller dimensions enable the material to retain their wire shape and resist deformation despite the large volume changes occurring. However, through an ex-situ electron microscopy study, it is shown here that this is not the case and the excellent performance of the electrode can in fact be attributed to a complete restructuring of the active material that occurs within the first 100 cycles, to form a continuous, porous, mechanically robust network of germanium ligaments. Chapter 4 describes the development of a simplified, scalable, solvent free method, rapid pyrolysis approach to fabricate germanium nanowire based Li-ion anodes, which again show excellent capacity retention and rate capability over extended cycles. Chapter 5 describes the synthesis of Ge/Si composite nanowire electrodes, wherein Ge nanowires are grown with Si nanowire branches extending from them. When utilised as Li-ion anodes, the material combines the stability and high rate capability of Ge with the higher capacity of Si. Finally, an investigation into the efficacy of nanowire electrodes based solely on Si is presented in chapter 6. The effect of electrolyte composition on the capacity retention of the material, and the compositional and electrochemical properties of solid electrolyte interface layer were investigated

High-performance germanium nanowire-based lithium-ion battery anodes extending over 1000 cycles through in situ formation of a continuous porous network

Here we report the formation of high-performance and high-capacity lithium-ion battery anodes from high-density germanium nanowire arrays grown directly from the current collector. The anodes retain capacities of similar to 900 mAh/g after 1100 cycles with excellent rate performance characteristics, even at very high discharge rates of 20-100C. We show by an ex situ high-resolution transmission electron microscopy and high-resolution scanning electron microscopy study that this performance can be attributed to the complete restructuring of the nanowires that occurs within the first 100 cycles to form a continuous porous network that is mechanically robust. Once formed, this restructured anode retains a remarkably stable capacity with a drop of only 0.01% per cycle thereafter. As this approach encompasses a low energy processing method where all the material is electrochemically active and binder free, the extended cycle life and rate performance characteristics demonstrated makes these anodes highly attractive for the most demanding lithium-ion applications such as long-range battery electric vehicles.ACCEPTEDpeer-reviewe

A Rapid, Solvent-Free Protocol for the Synthesis of Germanium Nanowire Lithium-Ion Anodes with a Long Cycle Life and High Rate Capability

A rapid synthetic protocol for the formation of high-performance Ge nanowire-based Li-ion battery anodes is reported. The nanowires are formed in high density by the solvent-free liquid deposition of a Ge precursor directly onto a heated stainless steel substrate under inert conditions. The novel growth system exploits the in situ formation of discrete Cu₃Ge catalyst seeds from 1 nm thermally evaporated Cu layers. As the nanowires were grown from a suitable current collector, the electrodes could be used directly without binders in lithium-ion half cells. Electrochemical testing showed remarkable capacity retention with 866 mAh/g achieved after 1900 charge/discharge cycles and a Coulombic efficiency of 99.7%. The nanowire-based anodes also showed high-rate stability with discharge capacities of 800 mAh/g when cycled at a rate of 10C

Review—Use of impedance spectroscopy for the estimation of Li-ion battery state of charge, state of health and internal temperature

The rapid adoption of electric vehicles (EVs) and the evolving needs of portable electronic devices has intensified the need for enhanced state diagnosis of Li-ion batteries (LIBs). As the applications for LIBs continue to grow, so too does their operational requirements; ranging from faster charging and improved safety to optimized energy control and extended lifespan. In order to keep pace with the growing requirements of LIBs, improvements in the monitoring of battery states must be achieved. Although electrochemical impedance spectroscopy (EIS) has existed since the 1960's, its potential as a diagnosis tool has only received widespread attention in recent years. In this paper, a detailed review on the applicability of impedance measurements for the estimation of the vital battery parameters of state of charge (SOC), state of health (SOH) and internal temperature (IT) has been performed