Yajuan Yu

Environmental characteristics comparison of Li-ion batteries and Ni–MH batteries under the uncertainty of cycle performance

An environmental impact assessment model for secondary batteries under uncertainty is proposed, which is a combination of the life cycle assessment (LCA), Eco-indicator 99 system and Monte Carlo simulation (MCS). The LCA can describe the environmental impact mechanism of secondary batteries, whereas the cycle performance was simulated through MCS. The composite LCA-MCS model was then carried out to estimate the environmental impact of two kinds of experimental batteries. Under this kind of standard assessment system, a comparison between different batteries could be accomplished. The following results were found: (1) among the two selected batteries, the environmental impact of the Li-ion battery is lower than the nickel-metal hydride (Ni-MH) battery, especially with regards to resource consumption and (2) the lithium ion (Li-ion) battery is less sensitive to cycle uncertainty, its environmental impact fluctuations are small when compared with the selected Ni-MH battery and it is more environmentally friendly. The assessment methodology and model proposed in this paper can also be used for any other secondary batteries and they can be helpful in the development of environmentally friendly secondary batteries.

Environmental Impact Assessment and End-of-Life Treatment Policy Analysis for Li-Ion Batteries and Ni-MH Batteries

Based on Life Cycle Assessment (LCA) and Eco-indicator 99 method, a LCA model was applied to conduct environmental impact and end-of-life treatment policy analysis for secondary batteries. This model evaluated the cycle, recycle and waste treatment stages of secondary batteries. Nickel-Metal Hydride (Ni-MH) batteries and Lithium ion (Li-ion) batteries were chosen as the typical secondary batteries in this study. Through this research, the following results were found: (1) A basic number of cycles should be defined. A minimum cycle number of 200 would result in an obvious decline of environmental loads for both battery types. Batteries with high energy density and long life expectancy have small environmental loads. Products and technology that help increase energy density and life expectancy should be encouraged. (2) Secondary batteries should be sorted out from municipal garbage. Meanwhile, different types of discarded batteries should be treated separately under policies and regulations. (3) The incineration rate has obvious impact on the Eco-indicator points of Nickel-Metal Hydride (Ni-MH) batteries. The influence of recycle rate on Lithium ion (Li-ion) batteries is more obvious. These findings indicate that recycling is the most promising direction for reducing secondary batteries’ environmental loads. The model proposed here can be used to evaluate environmental loads of other secondary batteries and it can be useful for proposing policies and countermeasures to reduce the environmental impact of secondary batteries.

Preparation of MnO2-Modified Graphite Sorbents from Spent Li-Ion Batteries for the Treatment of Water Contaminated by Lead, Cadmium, and Silver

Herein, a novel adsorbent was prepared via grafting MnO2 particles on graphite recovered from spent lithium-ion batteries to treat water contaminated by lead, cadmium, and silver. This is the first study reporting the recovery of spent LIB anode material and its application to heavy-metal-contaminated wastewater treatment. Characterizations using scanning electron microscopy, energy-dispersive X-ray analysis, and Fourier transform infrared showed that the adsorbent surface was coated with MnO2 ultrafine particles that served as the sorption mechanism to remove heavy-metal ions. In comparison to the raw artificial graphite (AG) powder, the MnO2-modified AG (MnO2-AG) exhibited a markedly improved removal capacity toward Pb(II), Cd(II), and Ag(I), whose removal rates reached as high as 99.9, 79.7, and 99.8%, respectively. The removal of the heavy metals by MnO2-AG was mainly through the ion exchange of hydroxyl groups. This study provides the possibility of synthesis of an efficient adsorbent by reusing the waste, such as spent Li-ion batteries. It is an economic and environmentally friendly approach for both heavy-metal-contaminated water treatment and waste recycling.

Quantifying the environmental impact of a Li-rich high-capacity cathode material in electric vehicles via life cycle assessment

A promising Li-rich high-capacity cathode material (xLi2MnO3·(1-x)LiMn0.5Ni0.5O2) has received much attention with regard to improving the performance of lithium-ion batteries in electric vehicles. This study presents an environmental impact evaluation of a lithium-ion battery with Li-rich materials used in an electric vehicle throughout the life cycle of the battery. A comparison between this cathode material and a Li-ion cathode material containing cobalt was compiled in this study. The battery use stage was found to play a large role in the total environmental impact and high greenhouse gas emissions. During battery production, cathode material manufacturing has the highest environmental impact due to its complex processing and variety of raw materials. Compared to the cathode with cobalt, the Li-rich material generates fewer impacts in terms of human health and ecosystem quality. Through the life cycle assessment (LCA) results and sensitivity analysis, we found that the electricity mix and energy efficiency significantly influence the environmental impacts of both battery production and battery use. This paper also provides a detailed life cycle inventory, including firsthand data on lithium-ion batteries with Li-rich cathode materials.

Management information system (MIS) for planning and implementation assessment (PIA) in Lake Dianchi

A kind of Management Information System for Planning and Implementation Assessment (PIA-MIS) is studied. The system is applied to the Lake Dianchi Watershed. MapInfo is selected as the system platform, Access is chosen as its database. MapBasic and Visual Basic are used as secondary development tools. PIA-MIS contains five parts: user management module; research module; statistical analysis module; database management module; display and output control module. The system can not only standardize the management of data monitoring and implementation status of the water pollution prevention program of Lake Dianchi, but also simulate and forecast the pollution condition of the whole lake. The system is meaningful to the assessment, anticipation, control and supervision of water quality. It provides a dependable basis for the future decision.

Rethinking environmental stress from the perspective of an integrated environmental footprint: Application in the Beijing industry sector

Individual footprint indicators are limited in that they usually only address one specific environmental aspect. For this reason, assessments involving multiple footprint indicators are preferred. However, the interpretation of a profile of footprint indicators can be difficult as the relative importance of the different footprint results is not readily discerned by decision-makers. In this study, a time series (1997-2012) of carbon, water and land footprints was calculated for industry sectors in the Beijing region using input-output analysis. An integrated environmental footprint (IEF) was subsequently developed using normalization and entropy weighting. The results show that steep increases in environmental footprint have accompanied Beijings rapid economic development. In 2012, the Primary Industry had the largest IEF (8.32); however, the Secondary Industry had the greatest increase over the study period, from 0.19 to 6.37. For the Primary Industry, the greatest contribution to the IEF came from the land footprint. For the Secondary and Tertiary Industries, the water footprint was most important. Using the IEF, industry sectors with low resource utilization efficiency and high greenhouse gas emissions intensity can be identified. As such, the IEF can help to inform about industry sectors which should be given priority for modernization as well as the particular footprints that require priority attention in each sector. The IEF can also be helpful in identifying industry sectors that could be encouraged to expand within the Beijing region as they are especially efficient in terms of value adding relative to IEF. Other industries, over time, may be better located in other regions that do not face the same environmental pressures as Beijing.

New Application of Waste Citrus Maxima Peel Derived Carbon as an Oxygen Electrode Material for Lithium Oxygen Batteries

Recently, lithium oxygen battery has become a promising candidate to satisfy the current large-energy-storage devices demand because of its amazing theoretical energy density. However, it still faces problems such as poor reversibility and short cycle life. Here, citrus maxima peel (CMP) was used as a precursor to prepare activated and Fe-loading carbon (CMPACs and CMPACs-Fe, respectively) via pyrolysis in nitrogen atmosphere at 900 °C, in which KOH was added as an activator. Electrochemical measurements show that CMPAC-based Li-O2 battery possesses high specific capacity of 7800 mA h/g, steady cycling performance of 466 cycles with a corresponding Coulombic efficiency of 92.5%, good rate capability, and reversibility. Besides, CMPACs-Fe-based O2 electrode delivers even lower overpotential in both charge and discharge processes. We conclude that these excellent electrochemical performances of CMPACs and CMPACs-Fe-based O2 electrode benefit from their cellular porous structure, plenty of active sites, and large specific surface area (900 and 768 m2/g), which suggest that these biomass-derived porous carbons might become promising candidates to achieve efficient lithium oxygen battery.

Does heavy metal hurt in the secondary battery production sites? The case study of occupational risk from Yangtze River Delta, China

ABSTRACT The purpose of this study was to determine the occupational health risk to employees of lithium-ion battery factories in Yangtze River Delta, China. Soil samples were collected from materials synthesis workshop and battery assembly line workshop, which are named site A, site N1, site N2, and site Z according to different battery products. We analyzed the heavy metals for Co, Cd, Mn, Cu, and Ni. The soil heavy metal exposure model and the health risk characterization model were built to assess occupational health risk. Besides, uncertainty analysis with the aid of Monte Carlo simulation was used to perform error propagation for model parameters. The health risk assessment with uncertainty results indicated that all the four sites have relative low risk of carcinogens for employees, and N1, A, and Z sites also have relative low risk of non-carcinogen for employees, but N2 site has value of 6.94, which is heavily higher than the threshold value (defined as 1.0). It means that the employees in N2 site are facing threat of the heavy metals. These results provide basic information of heavy metal pollution control and environment management in lithium-ion battery factory. It also answered the question of the occupational risk in the sites.

Optimization strategy integrity for watershed agricultural non-point source pollution control based on Monte Carlo simulation

This study has established a set of methodological systems by simulating loads and analyzing optimization strategy integrity for the optimization of watershed non-point source pollution control. First, the source of watershed agricultural non-point source pollution is divided into four aspects, including agricultural land, natural land, livestock breeding, and rural residential land. Secondly, different pollution control measures at the source, midway and ending stages are chosen. Thirdly, the optimization effect of pollution load control in three stages are simulated, based on the Monte Carlo simulation. The method described above is applied to the Ashi River watershed in Heilongjiang Province of China. Case study results indicate that the combined three types of control measures can be implemented only if the government promotes the optimized plan and gradually improves implementation efficiency. This method for the optimization strategy integrity for watershed non-point source pollution control has significant reference value.

Watershed pollution control plans effect assessment: Countermeasure adjustment modeling and simulation

As the effect of watershed pollution control planning is hard to evaluated, this paper brought forward a kind of methodology to assess the countermeasures effects on the water body. A kind of Artificial Neural Net (ANN) work called Radial Basis Function (RBF) was used to simulate the uncover interrelationships among the measures and the water quality indicators. After building their internal net, some certain input parameters which represents the environmental protection investments or alike in the net, were adjusted mandatorily. The variations of the output water quality indicators showed the effect of these countermeasures. The simulation result showed that investment on environmental protection is a positive index for water quality improvement.