The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the...The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the LIBs at low temperatures, the synergistic effects originating from the cathode, anode, electrolyte, and separators to the batteries are still not clear. Here, the 21700-type cylindrical batteries were evaluated at a wide range of temperatures to investigate the failure mechanism of batteries. Voltage relaxation, and the post-mortem analysis combined with the electrochemical tests, unravel that the capacity degradation of batteries at low temperature is related to the lithium plating at graphite anodes,the formation of unsatisfied solid deposited/decomposed electrolyte mixture phase on the anode, the precipitation of solvent in the electrolytes and the block of separator pores, and the uneven dissolved transition metal-ions from the cathode. We hope this finding may open up a new avenue to alleviate the capacity degradation of advanced LIBs at low temperatures and shed light on the development of outstanding low-temperature LIBs via simultaneous optimization of all the components including electrodes, electrolytes and separators.展开更多
基金supported by the National Natural Science Foundation of China (U1664255, 21875022, 51802020, U1564206)the National Key R&D Program of China (2016YFB0100301)+2 种基金the Science and Technology Innovation Foundation of Beijing Institute of Technology Chongqing Innovation Center (2020CX5100006)the Young Elite Scientists Sponsorship Program by CAST (2018QNRC001)support from Beijing Institute of Technology Research Fund Program for Young Scholars。
文摘The low-temperature performance of Li-ion batteries(LIBs) has important impacts on their commercial applications. Besides the metallic lithium deposition, which is regarded as one of the main failure mechanisms of the LIBs at low temperatures, the synergistic effects originating from the cathode, anode, electrolyte, and separators to the batteries are still not clear. Here, the 21700-type cylindrical batteries were evaluated at a wide range of temperatures to investigate the failure mechanism of batteries. Voltage relaxation, and the post-mortem analysis combined with the electrochemical tests, unravel that the capacity degradation of batteries at low temperature is related to the lithium plating at graphite anodes,the formation of unsatisfied solid deposited/decomposed electrolyte mixture phase on the anode, the precipitation of solvent in the electrolytes and the block of separator pores, and the uneven dissolved transition metal-ions from the cathode. We hope this finding may open up a new avenue to alleviate the capacity degradation of advanced LIBs at low temperatures and shed light on the development of outstanding low-temperature LIBs via simultaneous optimization of all the components including electrodes, electrolytes and separators.
