Assessment on the Use of High Capacity “Sn4_{4}P3_{3}”/NHC Composite Electrodes for Sodium-Ion Batteries with Ether and Carbonate Electrolytes

This work reports the facile synthesis of a Sn–P composite combined with nitrogen doped hard carbon (NHC) obtained by ball-milling and its use as electrode material for sodium ion batteries (SIBs). The “Sn$_{4}$P$_{3}$”/NHC electrode (with nominal composition “Sn$_{4}$P$_{3}$”:NHC = 75:25 wt%) when coupled with a diglyme-based electrolyte rather than the most commonly employed carbonate-based systems, exhibits a reversible capacity of 550 mAh g$_{electrode}$$^{−1}$ at 50 mA g$^{−1}$ and 440 mAh g$_{electrode}$$^{−1}$ over 500 cycles (83% capacity retention). Morphology and solid electrolyte interphase formation of cycled “Sn$_{4}$P$_{3}$”/NHC electrodes is studied via electron microscopy and X-ray photoelectron spectroscopy. The expansion of the electrode upon sodiation (300 mAh g$_{electrode}$$^{−1}$) is only about 12–14% as determined by in situ electrochemical dilatometry, giving a reasonable explanation for the excellent cycle life despite the conversion-type storage mechanism. In situ X-ray diffraction shows that the discharge product is Na$_{15}$Sn$_{4}$. The formation of mostly amorphous Na$_{3}$P is derived from the overall (electro)chemical reactions. Upon charge the formation of Sn is observed while amorphous P is derived, which are reversibly alloying with Na in the subsequent cycles. However, the formation of Sn$_{4}$P$_{3}$ can be certainly excluded

Enabling Aqueous Processing of Ni Rich Layered Oxide Cathode Materials by Addition of Lithium Sulphate

Aqueous processing of Ni rich layered oxide cathode materials is a promising approach to simultaneously decrease electrode manufacturing costs, while bringing environmental benefits by substituting the state of the art often toxic and costly organic processing solvents. However, an aqueous environment remains challenging due to the high reactivity of Ni rich layered oxides towards moisture, leading to lithium leaching and Al current collector corrosion because of the resulting high pH value of the aqueous electrode paste. Herein, a facile method was developed to enable aqueous processing of LiNi0.8Co0.1Mn0.1O2 NCM811 by the addition of lithium sulfate Li2SO4 during electrode paste dispersion. The aqueously processed electrodes retained 80 amp; 8201; of their initial capacity after 400 cycles in NCM811 graphite full cells, while electrodes processed without the addition of Li2SO4 reached 80 amp; 8201; of their capacity after only 200 cycles. Furthermore, with regard to electrochemical performance, aqueously processed electrodes using carbon coated Al current collector outperformed reference electrodes based on state of the art production processes involving N methyl 2 pyrrolidone as processing solvent and fluorinated binders. The positive impact on cycle life by the addition of Li2SO4 stemmed from a formed sulfate coating as well as different surface species, protecting the NCM811 surface against degradation. Results reported herein open a new avenue for the processing of Ni rich NCM electrodes using more sustainable aqueous route

Transport Transition Concepts

Detailed background for all transport scenarios and development pathways including all key parameters, and story-lines for the 5.0 °C, 2.0 °C and 1.5 °C transport scenario pathways. Mode specifc effciency improvement over time for road-, rail- and aviation transport technologies. Explanations of all vehicle technologies are included in the scenarios, along with the rationale for their selection. Description of key technology parameters for all relevant transport modes such as energy demand per passenger, and per freight tonne. Detailed regional breakdown for developments in regard to transport energy demand for ten world regions and all transport modes are provided

New insights into pre-lithiation kinetics of graphite anodes via nuclear magnetic resonance spectroscopy

Pre-lithiation of anode materials can be an effective method to compensate active lithium loss which mainly occurs in the first few cycles of a lithium ion battery (LIB), due to electrolyte decomposition and solid electrolyte interphase (SEI) formation at the surface of the anode. There are many different pre-lithiation methods, whereas pre-lithiation using metallic lithium constitutes the most convenient and widely utilized lab procedure in literature. In this work, for the first time, solid state nuclear magnetic resonance spectroscopy (NMR) is applied to monitor the reaction kinetics of the pre-lithiation process of graphite with lithium. Based on static 7Li NMR, we can directly observe both the dissolution of lithium metal and parallel formation of LiCx species in the obtained NMR spectra with time. It is also shown that the degree of pre-lithiation as well as distribution of lithium metal on the electrode surface have a strong impact on the reaction kinetics of the pre-lithiation process and on the remaining amount of lithium metal. Overall, our findings are highly important for further optimization of pre-lithiation methods for LIB anode materials, both in terms of optimized pre-lithiation time and appropriate amounts of lithium metal

A step towards understanding the beneficial influence of a LIPON-based artificial SEI on silicon thin film anodes in lithium-ion batteries

In this work, we present a comprehensive study on the influence of lithium phosphorus oxynitride (LIPON) as a possible “artificial SEI layer” on the electrochemical performance of pure silicon (Si) thin film electrodes for a possible application in microbatteries or on-chip batteries. Si thin film anodes (140 nm) with and without an additional amorphous LIPON surface layer of different thicknesses (100–300 nm) were prepared by magnetron sputter deposition. The LIPON surface coating was characterized thoroughly by means of electrochemical impedance spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. In situ electrochemical dilatometry and ex situ cross-section analysis of the electrodes after cycling could prove that the LIPON coating greatly diminishes the volume expansion of the Si electrode and, therefore, significantly improves the cycling stability and capacity retention. Furthermore, the LIPON coating remarkably reduces parasitic electrolyte decomposition reactions that originate from the Si volume expansion and contribute to the overall electrode volume expansion, as observed by the enhanced Coulombic efficiency over ongoing charge/discharge cycling. Overall, this article focuses on the preparation of optimized Si-based thin film electrodes in combination with LIPON solid electrolyte coatings for use in high-energy lithium ion batteries

Coating-Doping Interactions in commercial Ni-rich NCM Cathode Materials for high-energy Lithium Ion Batteries

Coming from the global picture of climate change and the crucial need to reduce greenhouse gases there is a huge demand for renewable energies. Innovations in different fields are necessary to account for the increased demand in generation, storage and distribution that evokes.The storage of green electricity is one example with the challenge that every application has different requirements in cost, lifetime, gravimetric and volumetric energy density. In the sector of individual mobility, a user will expect a comparable cost, safety and driving range of an electric car as the one that can be obtained from a combustion engine. Therefore, the future generations of battery systems in electric vehicles (EV) need to become cheaper and at the same time gain energy density.Ni-rich NCM-type layered oxide materials are promising candidates to satisfy those needs. The main advantages of increasing the Ni content lies in an increased energy density at the material level and the reduction of cobalt as critical raw material.There are however mayor drawbacks in terms of instability issues and cycling stability. Several mitigation strategies are often applied in literature such as doping to mitigate strong lattice parameter variations, coatings to protect the surface in contact with the electrolyte or core shell/gradient concentration design approaches. Although it is well-known that each of these approaches separately benefits the cycling stability of Ni-rich cathode materials, there are however no systematic reports investigating the simultaneous combination of two of the approaches.However a combination of coating and doping will be needed to overcome the instability issues for NCM materials with Ni contents above 90 %.In this work, the combination of Zr as frequently used dopant in commercial materials with W-coatingsis thoroughly investigated with a special focus on the impact of different processing conditions and post-processing temperatures. Beside material characterization via XRD, SEM, TEM and XPS also the electrochemical performance in Lithium ion batteries (LIBs) is reported. It sheds light onto the importance to not only investigate the effect of individual dopants or coatings but also the interactions between both

Ceramics for electrochemical storage

In this chapter, after having introduced the basics of electrochemical storage and types of secondary batteries, detailed focus is given on: (i) anode ceramic materials, (ii) cathode active materials, and (iii) separators and solid electrolytes. Chemistries of interest are based on lithium and sodium, covering both current commercial applications as well as technologies under development such as solid-state batteries