(Former Central Laboratory of Electrochemical Power Sources - CLEPS)

Institute of Electrochemistry and Energy Systems – IEES
(former Central Laboratory of Electrochemical Power Sources - CLEPS)
Acad. G. Bonchev Str., Block 10
1113 Sofia, Bulgaria


Director: Prof. Evelina Slavcheva Ph.D., D.Sc.
Phone: +359 2 872 2543; +359 2 971 1161
Fax: +359 2 872 2544
E-mail: ,   

The Institute of Electrochemistry and Energy Systems - IEES (former CLEPS), found in 1967, is an independent research institute of the Bulgarian Academy of Sciences (BAS). For over 40 years now IEES has been carrying out fundamental and applied research and development in the field of conventional and novel electrochemical systems, e.g. lead-acid batteries, lithium-ion cells, metal-air systems, Na-S batteries, etc. as well as on various  advanced methods for investigation and testing of energy sources.
A new research priority is the development and implementation of e-Science instruments for efficient collaboration and virtual research, especially in the field of Electrochemical Impedance Spectroscopy, and modern education.
The Institute has a long term tradition of active international collaboration with other international scientific organizations, public institutions and industrial R&D structures. For the last 10 years, IEES contractors and partners from all over the world have numbered more than 300. 
IEES is a host organization of a number of international and national structures:

EICIS - European Internet Centre for Impedance Spectroscopy
National Centre for Nanotechnologies
COSENT – regional COoperation of South-east Europe for Nano-Technologies
LABAT – international conference on Lead-Acid BATteries, held every 3 years
TK64 – Technical Committee for harmonization of Bulgarian batteries standards for with European ones
BED – Bulgarian Electrochemical Society.

The Institute is a member of the Bulgarian Hydrogen Society, BG GRID Society, and organizer of the Association of the Bulgarian Centres of Excellence – aBEST.

Academic staff of IEES:

2 Academicians (full members of BAS)
5 Professors (associate members of BAS)
16 Associate professors (associate members of BAS)

IEES Departments:

Electrochemistry of Lead-acid Batteries
Electrocatalysis and Electrocrystallization
Electrochemistry of Biocatalytic and Metal-air Systems
Solid State Electrolytes
Electrochemical Methods
Lithium Systems Electrochemistry
Nanoscaled Materials
Energy Efficiency

Major trends in the R&D work of IEES team in the last years:

New materials and new technologies for the production of lead-acid battery plates to meet the requirements for hybrid electric vehicles and photovoltaic system applications.
Hydrogen Energy. Novel approach to hydrogen generation and storage, metal-hydrides and fuel cells
Synthesis of high efficient, low cost intercalation compounds and nanostructured composite materials for Li-ion batteries
Various types of metal-air (e.g. Zn-air, Mg-air, Al-air, Fe-air) cells and batteries.
Electrochemical information systems (biosensors and enzyme electrodes)
Synthesis of isotropic and anisotropic metal and intermetal nanoparticles, nanowires, nanorods and nanochains containing hydrogen, boron or nitrogen, with tailored quantum-influenced properties
Advanced technique for Differential Impedance Analysis (DIA) with increased information capability and objectiveness of the impedance method
Models for the mechanism of the processes of crystallization during electro­deposition of metals, as well as the processes of adsorption and underpotential deposition of metals.