Influence of cell opening methods on organic solvent removal during pretreatment in lithium-ion battery recycling

The use and development of lithium-ion batteries (LIBs) are promoting the technological transformation of individual mobility, consumer electronics and electric energy storage. At their end of life, the complex compounds are disposed by different recycling technologies with defined secondary raw material production. The applied depollution temperatures of the process routes influence not only the recycling efficiency but also the process expenditure, design, medium and costs. Different pretreatment strategies in terms of dismantling depth and depollution temperature are existing. Furthermore, manual and mechanical methods for cell opening are distinguished, which together with the depollution leads to a respective organic solvent evaporation. In this contribution to LIB recycling, the influence of different dismantling depths, achieved by manual cell opening, on the thermal depollution of the LIB cells regarding the mass difference originating by organic solvent evaporation are quantified, in order to determine cell and equipment properties for a safe cell opening. As a result, combinations of thermal depollution and manual cell opening are discussed regarding technical and economic feasibility. The process medium and equipment properties for a safe cell opening are determined. Furthermore, recommendations for future industrial LIB waste management are presented.

Varroa destructor reproduction and cell re-capping in mite-resistant Apis mellifera populations

Globalization has facilitated the spread of emerging pests such as the Varroa destructor mite, resulting in the near global distribution of the pest. In South African and Brazilian honey bees, mite-resistant colonies appeared within a decade; in Europe, mite-resistant colonies are rare, but several of these exhibited high levels of “re-capping” behavior. We studied re-capping in Varroa-naïve (UK/Australia) and Varroa-resistant (South Africa and Brazil) populations and found very low and very high levels, respectively, with the resistant populations targeting mite-infested cells. Furthermore, 54% of artificially infested A. m. capensis worker cells were removed after 10 days and 83% of the remaining infested cells were re-capped. Such targeted re-capping of drone cells did not occur. We propose that cell opening is a fundamental trait in mite-resistant populations and that re-capping is an accurate proxy for this behavior.

Preparation of open cell rigid polyurethane foams and modified with organo-kaolin

The open cell rigid polyurethane foam (ORPUF) was prepared by adding chemical cell openers including O-500 and AK-9903. The FTIR results of cell openers and open cell rate of ORPUFs showed that O-500 has more effective cell opening capacity. In the ORPUF foaming formulation using O-500 as cell opener, silane coupling agent (KH-550) modified kaolin (organo-kaolin) was introduced into ORPUF with different weight loadings. The cellular morphology, apparent density, and compressive strength of the foams were tested in order to investigate the effects of organo-kaolin on the open cell rate and compressive property of the foams. The results showed that the open cell rate of ORPUFs slightly increased from 83.9% to 92.9% with the content of organo-kaolin. Meanwhile, compared to neat ORPUF, the compressive strength of foams increased by 72.8% when the content of introduced organo-kaolin was 4 parts per hundred of polyol by mass (php).