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Low and medium temperature pyrolysis technology is an important way of clean and utilization of low metamorphic coal. In this paper, three kinds of char samples were prepared in tube furnace according to different pyrolysis temperatures, and their combustion characteristics were compared by means of thermal analysis. Three modeless kinetic methods, KAS, FWO and Fredman, were used to study the combustion reaction activity under nonisothermal conditions from TG curve and DSC curve. In the end, Malek method is used to explore the mechanism function of the reaction process, and the results are analyzed numerically. The objective programming model and MATLAB are used to calculate the combined mechanism function of the reaction process. The results show that with the increase in the pyrolysis temperature, the combustion of char gradually shifts to the high temperature zone and shows a secondary effect between the volatile matter and the combustion characteristic temperature. The results show that the flammability index and burnout index increase first and then decrease, and the char prepared at 550 °C has the most developed pores and the best combustion performance with the increase in pyrolysis temperature, the average reaction activation energy decreases first and then increases, and the char prepared at 550 °C has the lowest activation energy. When the combustion heating rate is 5 °C min−1, the experimental curve and theoretical curve have a higher coincidence, and the combined mechanism function is adopted. The number is more suitable than the single most probable mechanism function to describe the combustion process of char. At this heating rate, the fuel reaction conforms to Z–L–T equation and reaction order model, which is limited by three-dimensional diffusion and chemical reaction. The distribution coefficients of the combined mechanism function are 0.4207 and 0.5886.

High ionic conductivity, good electrochemical stability, and satisfactory mechanical property are the crucial factors for polymer solid state electrolytes. Herein, fast ion conductor LiAlSiO4 (LASO) is incorporated into polyethylene oxide (PEO)-based solid-state electrolytes (SSEs). The SSEs containing LASO exhibit enhanced mechanical properties performance compared to pristine PEO-LiTFSI electrolyte. A reduced melting transition temperature of 40.57 °C is enabled by introducing LASO in to PEO-based SSE, which is beneficial to the motion of PEO chain and makes it possible for working at a moderate environment. Coupling with the enhanced motion of PEO, dissociation of the lithium salt, and conducting channel of LASO, the optimized composite polymer SSE exhibits a high ionic conductivity of 4.68 × 10−4, 3.16 × 10−4 and 1.62 × 10−4 S cm−1 at 60, 50 and 40 °C, respectively. The corresponding LiFePO4//Li solid-state battery exhibits high specific capacities of 166, 160 and 139 mAh g−1 at 0.2 C under 60, 40 and 25 °C. In addition, it remains 130 mAh g−1 at 4.0 C, and maintains 91.74% after 500 cycles at 1.0 C under 60 °C. This study provides a simple approach for developing ionic conductor-filled polymer electrolytes in solid-state lithium battery application.

With the proliferation of energy storage and power applications, electric vehicles particularly, solid-state batteries are considered as one of the most promising strategies to address the ever-increasing safety concern and high energy demand of power devices. Here, we demonstrate the Al4B2O9 nanorods-modified poly(ethylene oxide) (PEO)-based solid polymer electrolyte (ASPE) with high ionic conductivity, wide electrochemical window, decent mechanical property and nonflammable performance. Specifically, because of the longer-range ordered Li+ transfer channels conducted by the interaction between Al4B2O9 nanorods and PEO, the optimal ASPE (ASPE-1) shows excellent ionic conductivity of 4.35×10−1 and 3.1×10−1 S cm−1 at 30 and 60°C, respectively. It also has good electrochemical stability at 60°C with a decomposition voltage of 5.1 V. Besides, the assembled LiFePO4//Li cells show good cycling performance, delivering 155 mA h g−1 after 300 cycles at 1 C under 60°C, and present excellent low temperature adaptability, retaining over 125 mA h g−1 after 90 cycles at 0.2 C under 30°C. These results verify that the addition of Al4B2O9 nanorods can effectively promote the integrated performance of solid polymer electrolyte.

Porous CoTiO3 microbars have been successfully prepared by a facile solution way followed by thermal annealing in air. When evaluated as electrode materials for sodium ion batteries, unique 1D porous structure demonstrates remarkable sodium storage properties. The resultant CoTiO3 microbar electrodes exhibit not only higher discharge capacity (135.5 mA h g−1 at 300 mA g−1 after 500 cycles), but also more enhanced rate performance compared to those of CoTiO3 microparticle electrodes. The new findings reported here highlight the possibility for designing high-performance anode materials for sodium ion batteries.

In this work, a soft pack (20 Ah LiFePO4/MCMB) lithium ion battery is used as a prototype to develop a mathematical model and carry out a numerical simulation of the thermal properties associated with the cyclic process of a lithium ion power battery. This model incorporates the solvent reduction reaction on the anode, which is thought to be a dominant aging mechanism. Capacity fade is based on the loss of active lithium ions due to solvent reduction reaction on the anode and on the rise of anode film. The variation of internal ohmic heat, electrochemical reaction heat, and polarization heat of the battery during the constant-current discharge and constant-current and constant-voltage charge, as well as its relationship with capacity fading during the cyclic process are analyzed quantitatively. The results show that when a lithium ion battery is charging and discharging at a conventional rate, polarization and electrochemical reactions are the main causes for heat production. Capacity fading during the charging and discharge process affects both the charging and discharging time of the battery. It also affects the charging state of the electrode at a certain moment of charging or discharging, which changes the thermal behavior of the battery.

For recovery of Li, Co, Ni and Mn from the spent lithium-ion batteries, a novel leaching process involving amidosulfonic acid as leaching agent and d -glucose as reducing agent was developed. The effects of parameters including temperature, amidosulfonic acid concentration, solid-to-liquid ratio (S/L ratio), mass ratio of d -glucose to cathode materials ( d -glucose dosage) and leaching time on the leaching efficiencies of Co, Li, Mn and Ni were investigated. The leaching efficiencies reached 96.7% for Co, 98.4% for Li, 97.6% for Mn, and 98.3% for Ni under the most suitable conditions (90 °C, amidosulfonic acid of 1.5 mol L−1, S/L ratio of 50 g L−1, d -glucose dosage of 0.75, and 90 min). During the leaching process, with the dissolution of metals, the spherical particles of cathode materials firstly decomposed into small primary granules. Then valuable metals were further dissolved into leachate from these primary granules under the synergistic effect of H+ and d -glucose. Co-precipitation with oxalic acid recovered 99.9% of Co, 99.7% of Ni and 96.3% of Mn. The collected Co-Ni-Mn oxalate precipitates show homogeneous morphology and can be converted into well-shaped Co-Ni-Mn oxide by thermal treatment. Thus, the proposed process is found to be simple and efficient.