Amorphous Li-Al-Based Compounds: A Novel Approach for Designing High Performance Electrode Materials for Li-Ion Batteries

Abstract

A new amorphous compound with the initial atomic composition Al 43 Li 43 Y 6 Ni 8 applied as electrode material for Li-ion batteries is investigated. Unlike other amorphous compounds so-far investigated as anode materials, it already contains Li as a base element in the uncycled state. The amorphous compound powder is prepared by high energy ball milling of a master alloy. It shows a strongly enhanced specific capacity in contrast to amorphous alloys without Li in the initial state. Therewith, by enabling a reversible (de)lithiation of metallic electrodes without the phase transition caused volume changes it offers the possibility of much increased specific capacities than conventional graphite anodes. According to the charge rate (C-rate), the specific capacity is reversible over 20 cycles at minimum in contrast to conventional crystalline intermetallic phases failing by volume changes. The delithiation process occurs quasi-continuously over a voltage range

Binding Energy Referencing for XPS in Alkali Metal-Based Battery Materials Research (II): Application to Complex Composite Electrodes

“…Thus, the internal reference peaks have to be selected carefully, best procedure is to search for an element with a well-defined chemical state and to specify the absence of a differential charging shift there. This behavior is completely inverted if a similar amorphous alloy composition was selected, but Li was already introduced into the alloy during preparation [47]. AlNiY powder undoped and doped with Li and prepared by ball milling [44,46,47] were measured as pure powder and mixed with carbon black with the aim to minimize/remove the charging effects.…”

Preparation and Cycling Performance of Iron or Iron Oxide Containing Amorphous Al-Li Alloys as Electrodes

“…Nevertheless, besides improving properties of materials by modifying microstructures it is desirable to apply environmentally acceptable and cheap materials and to prove, whether already known working mechanisms can be transferred. In case of the amorphous alloys Al86Ni8Y6 and Al43Li43Ni8Y6 [1,2] it is useful to substitute the rare earth element Y and the health hazardous element Ni by alternative elements which serve the same purpose.…”

“…According to the Li-integration into Al86Ni8Y6, resulting in the master alloy Al43Li43Ni8Y6 [2], here Li is metallurgical blended into the conventional amorphous alloy Al78Fe13Si9, resulting in the new alloy Al39Li43Fe13Si5. As demonstrated [2] it is very important to provide Li already within the primary alloy, since otherwise the free volume of a Li-free amorphous network is too small to allow for a significant Li-insertion. Preparing such Li-containing amorphous alloys is not trivial because the conventional melt spinning process is not possible due to Li sprinkling.…”

“…The powder prepared in this way yielded a higher specific capacity and a better cycling stability than the same powder milled in a non-abrasive silicon nitride vial. This may be caused by Fe-oxide, which can also react with Li [2] by means of conversion reactions.…”

Frontiers of Energy Storage and Conversion

“…However, significant volume expansion limits their application as an anode [2][3][4]. In this context, Thoss et al reported a novel amorphous compound with the initial composition of Al43Li43Y6Ni8 as an electrode [5]. Their new intermetallic amorphous alloys could partially overcome the adverse effects on performance that result OPEN ACCESS from volume changes during electrochemical cycling.…”