Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at l...Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at least three levels: micro-scale, meso-scale and macro-scale. At the micro-scale, green chemistry carries out chemical activities such as chemical design and synthesis so that environmentally benign chemicals can be synthesized without using and generating hazardous substances. Green engineering, at the meso-scale, develops green industrial processes or clean technologies via pollution prevention and cleaner production, which will cause minimal damages or dangers to the environment and ecosystems when the product is manufactured and used. Industrial ecology at the industrial complex or community level seeks to optimize energy and materials use and minimize waste generation in industrial systems or communities by promoting planned materials and energy exchanges. Incorporation of ecological principles with the life cycle thinking in the chemical pathway synthesis, product design, process development, and industrial system and community planning appears to be the most promising engineering approach in achieving sustainable industrial development.展开更多
Li/MnO_(2) primary batteries are widely used in industry for their high specific capacity and safety.However,a deep comprehension of the Li^(+)insertion mechanism and the high self-discharge rate of the batteries is s...Li/MnO_(2) primary batteries are widely used in industry for their high specific capacity and safety.However,a deep comprehension of the Li^(+)insertion mechanism and the high self-discharge rate of the batteries is still needed.Here,the storage mechanism of Li^(+)in the tunnel structure of MnO_(2) as well as the dissolution and migration of Mn-ions were investigated based on multi-scale approaches.The Li/Mn ratio(at%)is determined at about 0.82 when the discharge voltage decreases to 2 V.The limited Li-ions transport rate in the bulk MnO_(2) restrains the reduction reaction,resulting in a low practical specific capacity.Moreover,utilizing spherical aberration-corrected transmission electron microscopy(TEM)coupled with electron energy loss spectroscopy(EELS),the presence of a mixed valence state layer of Mn^(2+)/Mn^(3+)/Mn^(4+)on the surface of the original 20 nm MnO_(2) particles was identified,which could contribute to the initial dissolution of Mn-ions.The battery separator exhibited channels for Mn-ions migration and diffusion and aggregated Mn particles.We put forward the discharge and degradation route in the ways of Mn-ions trajectories,and our findings provide a deep understanding of the high self-discharge rates and the capacity decay of Li-Mn primary batteries.展开更多
文摘Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at least three levels: micro-scale, meso-scale and macro-scale. At the micro-scale, green chemistry carries out chemical activities such as chemical design and synthesis so that environmentally benign chemicals can be synthesized without using and generating hazardous substances. Green engineering, at the meso-scale, develops green industrial processes or clean technologies via pollution prevention and cleaner production, which will cause minimal damages or dangers to the environment and ecosystems when the product is manufactured and used. Industrial ecology at the industrial complex or community level seeks to optimize energy and materials use and minimize waste generation in industrial systems or communities by promoting planned materials and energy exchanges. Incorporation of ecological principles with the life cycle thinking in the chemical pathway synthesis, product design, process development, and industrial system and community planning appears to be the most promising engineering approach in achieving sustainable industrial development.
基金supported by the National Natural Science Foundation of China(Nos.U2030206,12104022,52271014 and 22075003)the Presidential Foundation of CAEP(No.YZJJZL2023173)Sichuan Science and Technology Program(No.2021YFH0092).
文摘Li/MnO_(2) primary batteries are widely used in industry for their high specific capacity and safety.However,a deep comprehension of the Li^(+)insertion mechanism and the high self-discharge rate of the batteries is still needed.Here,the storage mechanism of Li^(+)in the tunnel structure of MnO_(2) as well as the dissolution and migration of Mn-ions were investigated based on multi-scale approaches.The Li/Mn ratio(at%)is determined at about 0.82 when the discharge voltage decreases to 2 V.The limited Li-ions transport rate in the bulk MnO_(2) restrains the reduction reaction,resulting in a low practical specific capacity.Moreover,utilizing spherical aberration-corrected transmission electron microscopy(TEM)coupled with electron energy loss spectroscopy(EELS),the presence of a mixed valence state layer of Mn^(2+)/Mn^(3+)/Mn^(4+)on the surface of the original 20 nm MnO_(2) particles was identified,which could contribute to the initial dissolution of Mn-ions.The battery separator exhibited channels for Mn-ions migration and diffusion and aggregated Mn particles.We put forward the discharge and degradation route in the ways of Mn-ions trajectories,and our findings provide a deep understanding of the high self-discharge rates and the capacity decay of Li-Mn primary batteries.
