The Li-ion battery (LIB) was first commercialized by Sony in 1991. Over the past twenty-five years, Li-ion technology has changed the world, enabling numerous technological advances in communications and mobility. It is also intimately linked to future energy management strategies to protect our planet. How did it happen? Having lived this adventure from the outset, we've been able to tell the story in detail. Progress has been gradual, involving different periods of scientific and technological advancement, often linked to societal demands. We have therefore described the evolution of technology through different eras. We began with the maturation period, which lasted two decades (1980-2000), with intensive work on electrode and electrolyte materials, doubling the capacity and durability of this technology in twenty years. However, the identified limitations of conventional materials prompted scientists to take risks. This led to a period of scientific euphoria (2000-2010) as the importance of nanomaterials and new Li reactivities such as alloying, conversion and even displacement reactions came to light.
Acceptance of Li ion technology for large-scale applications (electric mobility) came in 2008, with controversial debates over lithium resources and material abundance. This ushered in the era of sustainable battery development, with new research directions aimed at i) the use of abundant elements, ii) the development of less energy-intensive synthesis methods, iii) the use of electrodes of plant origin as an alternative to mineral approaches. In parallel with this, Li ion technology was given a new lease of life from 2013 with the demonstration of the possibility of using the electrochemical activity of cationic and anionic species within the same material. This represented a new paradigm for the design of capacitance-enhanced electrodes. Future developments in Li ion technology, whose cost per stored kWh is expected to fall below 100 euros by 2025, were also discussed. Mention was made, for example, of the importance of diagnosing the state of health of batteries through the use of sensors coupled to optical fibers, as well as of new research currently being carried out on battery self-repair.
