Periodic Reporting for period 3 - MOOiRE (Mix-in Organic-InOrganic Redox Events for High Energy Batteries)
Reporting period: 2021-09-01 to 2023-02-28
Organic and organometallic batteries emerge as one of the attracting alternative technologies for the forthcoming massive adoption of electrochemical energy storage (EES) systems. Indeed, these would allow to cope with raw material supply shortages, lead to a reduced environmental production and recycling footprint, and potentially result in an enhanced manufacturing scalability, globally improving the sustainability of EES devices. Whereas the gravimetric and volumetric energy metrics of organic or organometallic batteries may not currently compete with their inorganic counterparts, the natural abundance of their constituent elements (e.g. C, H, N, O but also Fe, Mn) and the expected mitigation of the battery life-cycle’s environmental burden constitute arguments of choice to counterbalance and eventually overthrow this already receding disadvantage.
One of the primary assets of the current Li-ion battery technology (large based on Cobalt) is the availability of positive electrode chemistries that are stable to ambient air in the lithium containing reduced form. Whereas there are many opportunities for the transition metal-based chemistries to fulfill these criteria, the organic-based compounds with alike properties remain finger-counted so far. The overall objectives are to explore and develop novel organic and organometallic chemistries bases on organic redox systems coupled with sustainable transition metals (such as Manganese, Iron). The challenge here is to render these systems comparable and competitive in terms of energy storage to the current Cobalt-based batteries. Organometallic (yet based on Iron or Manganese) chemistry can provide solutions to the low energy content of the current organic batteries in that it can help raising their voltage while also rendering these stable to air while containing the Lithium reservoir.
One of the primary assets of the current Li-ion battery technology (large based on Cobalt) is the availability of positive electrode chemistries that are stable to ambient air in the lithium containing reduced form. Whereas there are many opportunities for the transition metal-based chemistries to fulfill these criteria, the organic-based compounds with alike properties remain finger-counted so far. The overall objectives are to explore and develop novel organic and organometallic chemistries bases on organic redox systems coupled with sustainable transition metals (such as Manganese, Iron). The challenge here is to render these systems comparable and competitive in terms of energy storage to the current Cobalt-based batteries. Organometallic (yet based on Iron or Manganese) chemistry can provide solutions to the low energy content of the current organic batteries in that it can help raising their voltage while also rendering these stable to air while containing the Lithium reservoir.
The work during the initial phase of the project was focusing on confirming the project hypothesis on the design rules for redox active organometallic systems as well as identifying and testing new organic and organometallic redox chemistries. Amongts the most important achievement so far are
(i) proposing a new type of organometallic chemistry for lithium batteries. The chemistry is based on phendione-transition metal complexes and up to seven electron (per formula unit) charge storage was attained with these.
(ii) realizing the first type of electrically conducting Li-ion MOF cathode for energy storage. Based on a conventional organic redox chemistry (dihydro terephtalate), we achieved through structural and molecular engineering in MOF to raise the redox potential of this chemistry at above 3.2V (vs. Li/Li+) and build the first to date Li-ion MOF cathode.
(iii) developed a radically new organic redox chemistry with intrinsically high voltage and air stability while handled in ambient air.
(i) proposing a new type of organometallic chemistry for lithium batteries. The chemistry is based on phendione-transition metal complexes and up to seven electron (per formula unit) charge storage was attained with these.
(ii) realizing the first type of electrically conducting Li-ion MOF cathode for energy storage. Based on a conventional organic redox chemistry (dihydro terephtalate), we achieved through structural and molecular engineering in MOF to raise the redox potential of this chemistry at above 3.2V (vs. Li/Li+) and build the first to date Li-ion MOF cathode.
(iii) developed a radically new organic redox chemistry with intrinsically high voltage and air stability while handled in ambient air.
By realizing the first type of electrically conducting Li-ion MOF we have also defined the design rules for such systems that will be further exploited to enable higher energy content in organometallic battery systems. Further developments will rely on acquired expertise with these as well as novel chemistries with in particular focus on Li-rich MOF phases with mix-in multi-electron redox of both, transition metal nodes and organic linkers.