For the last 60 years Detchko Pavlov has been at the cutting edge of finding new ways to enhance the performance of lead acid batteries.

A lifetime in lead

“Detchko? He’s forgotten more about lead than I’ve ever known!“ The tribute coming from John Devitt, inventor of the VRLA battery and no intellectual slouch himself, is an indication of how much Detchko Pavlov has been admired and respected for half a century now.

His academic career started in 1948 when he obtained a place to read chemical engineering at the State University in Sofia. In 1953, after graduating with a degree in electrochemistry from the Higher Institute of Chemical Technology and Metallurgy in Sofia, he was invited to join the department. It was headed by professor Stefan Hristov, a pioneer in the application of quantum mechanics to electro-chemistry.

In the same department working alongside him as an assistant professor was a shy, pretty girl, Svetla Raitcheva, who had just completed her higher education at the D Mendeleev Chemical Technical Institute in Moscow and already had a reputation for academic brilliance and a fearsome intellect.

Detchko Pavlov

Their scientific collaboration grew into a friendship and ultimately, marriage. Svetla went on to earn her PhD in quantum chemistry and became first an associate professor and then a full professor. (She eventually chaired the Department of Physical Chemistry and also became head of the institute.)

At the 1960 National Congress of Chemists, Pavlov had reported the results of his research into polarography. Impressed, academician Kaishev, director of the department of electrochemistry at the Bulgarian Academy of Sciences, invited Pavlov to join the department.

It was an auspicious time to specialize. Bulgaria had begun to concentrate its manufacturing efforts in producing electric forklift trucks and Pavlov was assigned the task of researching how to improve lead acid batteries.

For the next half a century, working on the fourth floor of Building 10 on the Bulgarian Academy of Sciences campus, Pavlov and his team of some 25 co-workers — the best graduates from the University of Chemical Technology and Metallurgy and the Faculties of Chemistry and Physics of the Sofia State University — have been breaking new ground in understanding the processes at work in a battery.

In 1961, Pavlov obtained a one-year posting at the Institut du Radium, Marie and Pierre Curie Laboratory in Paris, France, working for the laboratory director, professor Haisinski, who had once worked with Marie Curie. Haisinski directed Pavlov towards research on the chemistry of complex anode processes and in particular moving research into practical applications.

LABD formation 

In 1967, Pavlov and his colleague, professor Evgeni Budevski, established the Central Laboratory of Electrochemical Power Sources (CLEPS), in which he became the head of the Lead Acid Battery Department (LABD).

Following the discovery of rich deposits of lead ores in southern Bulgaria, in the mid-1960s, the country became the major supplier of forklift trucks and batteries to the USSR and other eastern bloc countries. Alongside their scientific research, the LABD scientists actively supported the Bulgarian battery industry with new technologies, transfer of knowledge and genuine theoretical modelling.

For example, Pavlov and colleague Vasil Iliev proved that when polymer additives are added to the battery, its power at low temperatures increases.

Their scientific contribution paid off. The starter batteries produced in the Bulgarian “Start” factory in Dobritch continued to work well in freezing and sub-zero temperatures.

With Yugoslavia, Czechoslovakia, East Germany and Tyumen unable to provide anything comparable, Bulgarian batteries were bought in large quantities, starting at 300,000 units and rising. In return, Bulgaria received 12,000-15,000 automobiles per year from the Zhiguli-Lada factory in the Soviet city of Toliati.

The range of studies conducted by Pavlov and his team has been extensive. These include: the kinetics of electrochemical processes; electrochemistry of lead electrodes; semiconductor properties and structure of lead oxides, lead sulphate and basic lead sulphates; processes related to all stages of the technology of battery manufacture including paste mixing, curing, drying, pickling and formation; structures of lead and lead oxide active masses; processes taking place inside the battery during its storage, operation and rest; electrochemistry of antimony and tin electrodes; processes of oxygen evolution and its recombination back to water; thermal phenomena in VRLAB and the mechanism of the processes causing thermal runaway in VRLAB, degradation processes and the ways to suppress or avoid them.

Of special note was the way Pavlov and his team investigated the way in which expanders affected the performance of negative lead acid battery plates and how they could be improved.

This led to the creation of a new generation of highly efficient organic ligno-sulphonate expanders. The team also revealed the mechanism of the processes taking place in the AGM separator and developed a modified, better AGM with programmable properties.

In consequence, Pavlov and his team have been granted 33 patents, in Bulgaria and abroad. He also developed a lecture course “Processes that occur during battery manufacture” and “Essentials of Lead Acid Batteries”, which he has presented in 17 countries worldwide.

A second family 

With his researches came international acknowledgement as Pavlov’s team’s work was recognised for its worth.

One of the more charming characteristics of Pavlov — who has a reputation for being a modest, easy-going person — is the way that he has never distinguished his work from that of his team. Indeed when his wife was alive the two often referred to the team as their second family.

Pavlov was awarded a Doctor of Science degree in 1984 — a belated qualification. Fully occupied at CLEPS, he simply had not found the time to make a conventional approach. So when he submitted his thesis, the Scientific Council of Physical Chemistry — the toughest in Bulgaria — agreed that this was not merely a PhD work, but something much bigger. They awarded him a DSc.

From 1988, he was the driving force behind the success of the LABAT series of conferences which have since been held every three years. As testimony to their importance, the proceedings of these meetings have been published as special issues of the Journal of Power Sources. He has also served for many years as a distinguished member of the International Advisory Board of the journal.

Pavlov initiated the decision of the Bulgarian Academy of Sciences to award battery scientists and experts with the Gaston Planté medal for outstanding contributions. Up to now, 11 battery men from seven countries have received this award.

Pavlov and his wife Svelte Rycheva

In the early 1990s with the Republic of Bulgaria undergoing rapid democratic changes — and the economy being hit by rising inflation and falling standards of living — Pavlov realized there was a risk that the department he had been building up for more than 25 years could fall apart. He introduced what he called “the American approach to science” — essentially using commercial partners to boost his research efforts.

Before long he had persuaded international concerns such as Varta Research in Germany, ALABC in the USA and Oerlikon in Switzerland to offer his department remunerative several-year contracts to develop production technologies.

Academician 

In 1997 he was elected a full member, or academician of the Bulgarian Academy of Sciences. This is the highest scientific rank in eastern Europe. It is only when one academician dies that a new one can be elected.

That year he also became adviser and cooperative member of the ITE Battery Research Institute, Nagoya, Japan.

Pavlov and his team — research scientists Geno Papazov, Stefan Ruevski, Temelaki Rogachev, Boris Monahov, Galia Petkova, Mitko Dimitrov, Plamen Nikolov, Maria Matrakova and others have written extensively and some 195 papers have been published in international scientific journals. To-date, these have been cited more than 2,700 times in scientific literature worldwide. Often, just one of these papers would go through as many as 16 drafts before he was satisfied. Among his more recent monographs is “Essentials of Lead-Acid Batteries”, published in 2006.

The value of Pavlov’s contribution has been acknowledged through a huge range of awards and honours.

Admirers say the genius of Pavlov has been in the way he can pinpoint where a problem might be occurring in, say, a piece of battery production or use, then strip the processes down to fundamental methods. Once the process has been elaborated he is also famous for the clarity of his writing so that not just academics but any production engineer can use it to their practical or theoretical ends.