Innovation provider

Jagiellonian University

Contact

e-mail: radoslaw.rudz@uj.edu.pl
phone: +48 12 663 38 32
fax: +48 12 663 38 31

Description

Lithium-ion (Li-Ion) batteries are devices for collecting and transmitting electricity with the highest energy storage capacity per weight and volume. Commonly they are used in cell phones, digital cameras and notebooks, but also in the measuring apparatus, electro-tools, telemetry systems, satellite communications, or in a hybrid-powered (HEV) and
electric cars (EV).
Battery negative electrode is made of porous carbon or graphite while positive electrode of transition metal oxides (cobalt, manganese or nickel). Conductive carbon layer designed to the electrode layers are usually
obtained by pyrolysis of organic compounds or polymers. For this purpose physical mixtures are prepared or organic solvents are used. Previous carbon layers obtained by pyrolysis of organic materials do not show appropriate surface morphology and sufficient high electrical conductivity. Conductive carbon layers used for lithium batteries should have a low surface of contact with electrolyte in order to reduce the SEI layer (Solid-Electrolite Interphase), while strictly adhere to the surface of electrochemically active material. Moreover, they should have a sufficient electrical conductivity, as well should not impede the transport of lithium ions between the electrolyte and active material during charge and discharge processes.

Advantages

Significant advantages of the presented solutions are:
  • chemical composition of the mixture, which is a precursor of carbon layers,
  • the new use of hydrophilic polymers with N-vinylformamide to receive the carbon layers and films,
  • method of to obtaining the nano-carbon layer with a specific surface morphology,
  • improvement of the chemical stability of composite cathode materials.

Innovative aspects (ecologic, social and economic)

In the comparison to existing solutions the novelty of presented invention is method of carbon precursor marking, which proceeds completely in the water environment and its composition allowing to obtain strictly adherent layer of controlled porous structure. Moreover carbon precursors are nontoxic, which makes the technology more safety and less onerous for the environment. Appropriately chosen carbon precursor composition allow to obtain expected and required physicochemical properties of the carbon layer (thickness, tightness, porosity, etc.). In particular, it should be emphasized the possibility of receiving suitable electrical conductivity of the carbon layer (>10-3 Scm-1) above the temperature level of 400°C.

Application examples

C/Al2O3, C/LiMn2O4 and C/LiMn2O4-ySy conductive carbon layers have been received and experimentally tested. The carbon content in the composite, its electrical properties, thermal and chemical stability as well as the surface morphology have been determined. Test results have indicated a good properties of the layer and the possibility of their use in both positive and negative electrodes of lithium batteries.

Cost

Downloads

Current stage of development

Available for demonstration – field tested

Intellectual Property Rights

Patent applied for

Country of origin

Poland

Country of application

Year

2012

National Contact Point

dr Włodzimierz A. Sokół
National Contact Point for Eco-efficient Technologies and Management Systems
Central Mining Institute (GIG)

Plac Gwarkow 1
40-166 Katowice
Poland

Tel: +48 32 259 22 11
Fax: +48 259 22 11

w.sokol@gig.eu
www.actclean.gig.eu