Christophe Forgez is a uni­ver­si­ty pro­fes­sor and research sci­en­tists at UTC’s Rober­val Lab­o­ra­to­ry. Until July 2024, he head­ed the «Mecha­tron­ics, actu­a­tors, robo­t­i­za­tion and sys­tems» Depart­ment. His research focus­es on inno­v­a­tive bat­ter­ies for elec­tric vehicles.

Christophe Forgez was recruit­ed as an automa­tion engi­neer at the Com­piègne Electro­mechan­ics Lab­o­ra­to­ry (LEC), which merged with the UTC Rober­val Lab­o­ra­to­ry in 2018. Among his research activ­i­ties? «One of the aims of my research is to estab­lish diag­no­sis laws. Ini­tial­ly, it was for elec­tri­cal pow­er units, in par­tic­u­lar starter-alter­na­tors, as part of a joint lab­o­ra­to­ry organ­ised between Valéo and LEC. In a way, we were already work­ing on the begin­nings of hybridiza­tion. For me, it was a mat­ter of mon­i­tor­ing the core tem­per­a­ture of these units to avoid them being dam­aged. The LEC drew on sev­er­al areas of exper­tise: one was in the design of elec­tri­cal machines and their spe­cif­ic con­trols and anoth­er was in pow­er elec­tron­ics. We spe­cialised in on-board elec­tri­cal ener­gy sys­tems, in par­tic­u­lar elec­tric pow­er-trains for vehi­cles, but lacked the bat­tery com­po­nent as an ener­gy source. There­fore, it was quite nat­ur­al for me to take an inter­est in this area,» he explains.

It’s an area of research he’s been devel­op­ing since the 2000s. «Since the ear­ly 2000s, I’ve been devel­op­ing mod­els that I ini­tial­ly used for diag­nos­tic func­tions. In oth­er words, to ensure that the elec­tron­ics and IT used around the bat­tery can mon­i­tor and ensure its prop­er func­tion­ing. These algo­rithms are embed­ded in a BMS (Bat­tery Man­age­ment Sys­tem), which is essen­tial for all lithi­um-ion bat­ter­ies, and is respon­si­ble for check­ing that there is no risk of over­heat­ing or explo­sion. We are also work­ing on sub­jects such as age­ing, in order to be able to pre­dict a battery’s life expectan­cy. This is a top­ic designed to meet the busi­ness plan of a com­pa­ny wish­ing, for exam­ple, to elec­tri­fy a pow­er-train, and which would there­fore like to know the size of its bat­tery pack accord­ing to the tar­get­ed appli­ca­tion, as well as the lifes­pan of the bat­ter­ies. In con­ven­tion­al use, for exam­ple, man­u­fac­tur­ers would aim for bat­ter­ies and vehi­cles to have the same ser­vice life,» empha­sizes Christophe Forgez.

With the rise of elec­tro­mo­bil­i­ty, these themes are of inter­est to a large num­ber of play­ers in both acad­e­mia and indus­try. «UTC is a mem­ber of the «Com­mutes» con­sor­tium, which includes the CEA, IFPEN, the IMS lab­o­ra­to­ry in Bor­deaux, the Gus­tave Eif­fel Uni­ver­si­ty in Lyon and EIGSI, an engi­neer­ing school in La Rochelle. The aim of the con­sor­tium? The aim is to pool our test­ing resources and offer indus­tri­al part­ners one-year test cam­paigns to try and under­stand how bat­ter­ies become degrad­ed under cer­tain con­di­tions, so as to build up data­bas­es that can be used to pro­duce more robust mod­els. For exam­ple, we’ve been work­ing on cold charg­ing to see how bat­ter­ies behave in extreme cold, so as to define charg­ing pro­to­cols. I also have direct, recur­ring part­ner­ships with man­u­fac­tur­ers such as Renault and Safran… This enables me to fund the­ses for three years on a prob­lem framed in con­sul­ta­tion with the com­pa­ny», he explains.

Innovative batteries

Until now, the aim of this research work has been to make bat­ter­ies more reli­able, more robust and also more durable. «Today, we’re try­ing to go fur­ther by devel­op­ing inno­v­a­tive bat­ter­ies. The aim is to deter­mine dif­fer­ent ways of using bat­ter­ies. How, for exam­ple, can we speed up charg­ing? At present, a 5‑minute charge is not pos­si­ble, but we’re work­ing in this direc­tion. The idea is to val­i­date our mod­els so that they are suf­fi­cient­ly reli­able. Exper­i­men­tal­ly, we cur­rent­ly know how to charge a bat­tery cell in 10 min­utes at zero degrees, with­out dam­ag­ing it. This con­trol law can be trans­posed to the vehi­cle scale to mon­i­tor the smooth run­ning of charges last­ing around 20 or 30 min­utes, and to ensure that at no point does this rapid charge lead to pre­ma­ture degra­da­tion», con­cludes Christophe Forgez. 

MSD