Evolutive waves in electrochemical batteries

We are now entering an epoch-making evolution in energy supply, in the framework of decarbonization and ecological transition, which are strongly addressed in Europe and other countries and continents. The phase-out of fossil fuels and the expansion of renewable sources, notably photovoltaic and wind that are intermittent and unpredictable, on one side, and the advent of electric vehicles on the other side, will imply a growing need for electrochemical batteries in both stationary and mobile versions. Huge research programs are under development to provide better and cheaper cells able to meet the future demand. However, when we look at the past of electrotechnology, we see that batteries have already played major roles in the evolution of electrotechnology, starting with the first cell, invented by Alessandro Volta in 1799, that allowed electricity to get rid of the narrow limitations of electrostatics. Over more than half a century, primary cells derived from Volta’s invention powered the early exploitations of electricity. When reliable electromechanical generators appeared, capable of delivering cheap and large power, secondary (rechargeable) cells were developed, which were instrumental in the first season of electric vehicles, at the turn of the century, both above ground and underwater. Just after the mid of the 20th century the advent of the transistor and solid-state electronics allowed the downsizing of many appliances. However, devices like hearing aids and radio receivers called for compact and better performing cells to became portable and the answer consisted in a new generation of primary cells, in particular alkaline. Shortly after, space exploration called for new generations of rechargeable batteries, mostly based on Nickel-based chemistries (Ni-Cd, Ni-H2, Ni-MH), which found application also in other fields. Toward of the end of the century, new scientific horizons were opened by the lithium technologies, first in primary cells and then in secondary ones. The evolution of rechargeable lithium-ion battery was gradual, being implemented first in low-power portable electronics (mobile phones, laptops, organizers, media players, … rated 5-60 Wh), then in middle-power electric vehicles (HEV, PHEV, BEV, with power and energy ranging as 5-600 kW and 1–100 kWh), and in both fields they quickly became dominating. Still afterward, large stationary Li-ion (up to 150 MW and 300 MWh) started to be installed in support of electric grids with power for discharge durations up to 4 hours.