Hell’s jour­ney for LiI­on batteries

The wave of e‑mobility is cres­ting. And it’s mas­si­ve. It’s asso­cia­ted with the deve­lo­p­ment and tes­ting of new tech­no­lo­gies in pre­vious­ly undreamt-of dimen­si­ons. At Phoe­nix Test­lab in Blom­berg, lithi­um-ion bat­te­ry packs weig­hing up to 800 kg are tes­ted. A look behind the sce­nes at a modern tor­tu­re chamber.

T he topic is a pro­ver­bi­al­ly hot one: again and again, reports of electric vehi­cles star­ting on fire haunt the news. The topic of accu­mu­la­tors is beco­m­ing incre­as- ingly explo­si­ve due to the enor­mous ener­gy den­si­ty requi­red and their use in ever­y­day life on wheels. And with this also come things like dura­bi­li­ty, per­ma­nent load, and safe­ty. This is why Phoe­nix Test­lab in Blom­berg is one of the very prime addres­ses for the auto­mo­ti­ve industry.

We’re making bat­te­ries old. And very quick­ly.” The per­son say­ing that isn’t wea­ring a magic hat and doesn’t own a time machi­ne. Micha­el Jon­ca heads the bat­te­ry labo­ra­to­ry at Phoe- nix Test­lab. Not only does he come across as extre­me­ly like- able, but also as very respec­ta­ble. So no hocus-pocus, but real tech­no­lo­gi­cal­ly pionee­ring work to tack­le the ener­gy sources for e‑vehicles.

The lords of time travel

Our job is to arti­fi­cial­ly age lithi­um-ion bat­te­ries in the pro­to­ty­pe sta­ge. With our sophisti­ca­ted test methods, we stress the sen­si­ti­ve ener­gy sources to such an extent that it cor­re- sponds to far more than what is sus­tai­ned over one vehi­cle ser­vice life.” A vir­tu­al time machi­ne. A litt­le magic after all! “We strict­ly fol­low the manu­fac­tu­rers’ spe­ci­fi­ca­ti­ons,” Jon­ca says, exp­lai­ning his tasks. 

The bat­te­ry test laboratory

Phoe­nix Test­lab is an inde­pen­dent test insti­tu­te found- ed in 1994 by Phoe­nix Con­ta­ct and which is now ope­ra­ting under the name Phoe­nix EMV-Test GmbH. The rea­son it was foun­ded was the elec­tro­ma­gne­tic com­pa­ti­bi­li­ty test (EMC for short), which has been man­da­to­ry sin­ce that time. From the very begin­ning, the inde­pen­dence of the insti­tu­te was an important fea­ture of the test labo­ra­to­ry, des­pi­te its pro­xi­mi- ty to the foun­ding com­pa­ny. This inde­pen­dence is one of the cor­ner­stones for the rapid suc­cess of this high-tech com­pa­ny. Ano­t­her one is that the cus­to­mer is king.

The­re­fo­re, in the hal­lo­wed halls at Königs­win­kel 10, strict cus­to­mer spe­ci­fi­ca­ti­ons often app­ly. “Sor­ry, but the­se devices and test objects are off-limits to pho­to­graph­ers.” This app­lies espe­cial­ly to the auto­mo­ti­ve indus­try. Sin­ce 2011, Phoe­nix Test­lab has been an almost indis­pensable part­ner for the­se com­pa­nies and their up to 800-kilo­gram ener­gy sto­rage sys­tems. In spring of this year, one of the most modern labo­ra­to­ries in the ent­i­re indus­try for tes­ting lithi­um-ion bat­te­ries and modu­les began ope­ra­ti­on on an area of appro­xi­mate­ly 950 squa­re meters.

The con­struc­tion of this test cen­ter began with the­se con- tai­ners.” Tog­e­ther with Tho­mas Worsch, the mar­ke­ting expert from Phoe­nix Test­lab, we start a tour of the test insti­tu­te. “Con­tai­ners are ide­al becau­se we can hand­le the respec­ti­ve test com­ple­xes and the test spe­ci­mens indi­vi­du­al­ly for safe- ty rea­sons,” Micha­el Jon­ca exp­lains. “Alt­hough we don’t test any dest­ruc­tion sce­n­a­ri­os here, so we don’t inten­tio­nal­ly ex- pose the test object to dest­ruc­ti­ve for­ce. But our dura­bi­li­ty and ser­vice life tests also stress the lar­ge bat­te­ries con­si­der­ab­ly. ””The­re­fo­re, the­re is also a very clo­se coope­ra­ti­on with the lo- cal fire bri­ga­de, which has to quick­ly get a poten­ti­al fire under con­trol without end­an­ge­ring the rest of the test lab and the employees and sur­roun­ding residents.”

In the tor­tu­re chamber

The lar­ge bat­te­ry blocks are sub­jec­ted to mon­ths of hard work The first stop is the electri­cal test faci­li­ty. “We’re char­ging at full power here, boos­ting to full char­ge in an hour or two. Several thousands of times. Our power con­sump­ti­on is the­re­fo­re simi­lar to that of the ent­i­re Phoe­nix Con­ta­ct pro­duc­tion in the neighborhood.” 

No won­der then that, at the end of this test run, the test objects are left to sit for one or two weeks until they are retur­ned to the cli­ent. “The chem- ical reac­tions in the bat­te­ry don’t end abrupt­ly; they con­ti­nue for awhile,” exp­lains the head of the bat­te­ry labo­ra­to­ry. “The dan­ger of igni­ti­on during tran­sit would be too gre­at to return them immediately.”

Shaking for the ship­ping industry

Things are get­ting mecha­ni­cal. We march to the next tor­tu­re cham­ber. It sounds like a fair­ground: “This is our shaker, our shaking cham­ber. Here we shake the bat­te­ry pack for about two weeks unin­ter­rup­ted, com­bi­ned with an envi­ron­men­tal cham­ber so that we can simu­la­te heat and cold.” The dimen­si­ons of the test stand, which is as tall as a house, are enor­mous. “We lift the test object tog­e­ther with its aggre­ga­te frame, which we’ve manu­fac­tu­red, into place with a five-ton cra­ne.” The steel shaking pla­te alo­ne weighs 35 tons. It’s spring-moun­ted in the foun­da­ti­on, other­wi­se the ground would trem­ble in a wide radi­us around it,” reports Tho­mas Worsch. Jon­ca adds, “Here, we also test com­pon­ents from ship­ping and indus­try, not just bat­te­ries, but also ent­i­re con­trol cabinets.”

The test stand vibra­tes using the “unia­xi­al vibra­ti­on method”. To shake a test object in all three dimen- sions, its posi­ti­on on the test sys­tem is chan­ged. The test stand also has one more nas­ty sur­pri­se for the spe­ci­mens: “We also simu­la­te a mecha­ni­cal shock, such as dri­ving over a curb. That’s a load of up to 50 g on the test object.”

The T‑Shocker

The bat­te­ries some­ti­mes spend six mon­ths, some­ti­mes even almost a year and a half, in the Phoe­nix Test­lab, depen­ding on cus­to­mer requi­re­ments. The piti­ful endu­ran­ce run­ners can’t avoid the next mar­tyr­dom test: the T‑shocker. “For ten to thir­ty days, the bat­te­ry pack must be able to with- stand a tem­pe­ra­tu­re drop of ‑40 °C to +75 °C. The­se are very typi­cal deman­ds in the auto­mo­ti­ve indus­try,” Micha­el Jon­ca says, let­ting us mar­vel. “Here, the strength of the outer casing is strained.”

Last hurd­le swim­ming pool

If the test object is still in a good mood up to this point, the next tor­tu­re loo­m­ing ahead will place it in the plun­ge pool. “This lar­ge pool is brand new,” Jonca’s voice echoes through the spe­cia­li­zed swim- ming space. On the cei­ling is the lar­ge cra­ne that lifts the bat­te­ries into cold or warm water. “We can also heat the water.” 

At the plun­ge pool the bat­te­ries go bathing

A team of engi­neers and staff is respon­si­ble for each bat­te­ry pack, sin­ce the respec­ti­ve test pro­ce- dures are com­ple­te­ly dif­fe­rent. “At the moment, we’re tes­ting twel­ve dif­fe­rent test objects, and the­re­fo­re also twel­ve dif­fe­rent ener­gy sources, for their respec­ti­ve electric vehi­cles.” If you accom­pa- ny the nice Mr. Jon­ca through his tor­tu­re cham­bers, you can be sure that the test objects that escape unhar­med here will endu­re almost any tor­tu­re with ease.

Phoe­nix Testlab

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