Demand for electrochemical storage devices is rising sharply, driven in particular by the requirement of automotive industry. Lithium-ion batteries are currently the leading candidates to fullfil this demand. However electrode materials rely on critical elements (e.g. Li, Co and/or Ni) due to their natural abundance, geographical availability and the costly, highly energy-intensive extraction and/or recycling processes. Organic electrode materials, which are exclusively based on very abundant elements (C, H, N, S, P and O) and could be derived from biomass, are more and more proposed as a viable and robust alternative to support the development of metal-ion technology. Their synthesis processes are more flexible and less energy consuming. Furthermore, these materials can be in principle recycled at their end of life by combustion, enabling them to be reintegrated into the carbon cycle and limiting the production of persistent wastes in the environment.
Moreover they benefit from the richness of organic chemistry and electrochemical properties such as redox potentiel can be finely tuned at molecular level by adding functional groups with electron-donating or electron-attracting effects. This presentation will discuss the isomerisation of a quinone derivative : dilithium(2,5-dilithium-oxy)terephthalate salt (also known as Li₄-p-DHT), and its use as N-type positive electrode material. Its working potential can be modulated from 2.55 V vs. Li/Li⁺ to 3.45 V vs. Li/Li⁺ depending on structural analogues. We will demonstrate that the isomerisation of the carboxylate functions that provide insolubility can also affect the electrochemical properties of the structure in terms of potential adjustment but also reachable capacity. This presentation will go over all development related to this new carboxyphenolate-based material as a positive electrode material, from synthesis to electrode formulation and electrochemical tests.