Balancing loading mass and gravimetric capacitance of NiCo-layered double hydroxides to achieve ultrahigh areal performance for flexible supercapacitors

Delivering high areal capacitance(CA)at high rates is crucial but challenging for flexible supercapacitors.CA is the product of areal loading mass(MA)and gravimetric capacitance(CW).Finding and understanding the balance between MA and CW of supercapacitor materials is significant for designing high-CA electrodes.Herein,we have systematically studied the correlation between MA and CW of the nanosheet arrays of NiCo-layered double hydroxide(NiCo-LDH),which were electrodeposited on carbon cloth with different heights to adjust the MA,accompanied by the interlayer distance regulation to improve the CW.The optimal CW performance is achieved at the best charge transfer kinetics for each of MA series.The NiCo-LDH electrode with the suitable MA(2.58 mg cm^(-2))and the relatively high CW(1918 F g^(-1) at 5 A g^(-1) and 400 F g^(-1) at 150 A g^(-1))present a high CA of 4948 mF cm^(-2) at 12.9 mA cm^(-2) and a record-high 1032 mF cm^(-2) among LDHs-based flexible electrodes at an ultrahigh current density of 387 mA cm^(-2).The corresponding flexible supercapacitor coupled with activated carbon delivers a high energy density of 0.28 mWh cm^(-2) at an ultrahigh power density of 712 mW cm^(-2),showing great potential applications.

A review of China's automotive industry policy:Recent developments and future trends

To promote the improvement and development of China's automotive industry policy,this study conducts a systematic review and hierarchical analysis of both domestic and international automotive industry policies.First,the automotive industry policies of the United States,Germany,South Korea,and Japan are summarized in terms of their industrial structure adjustment,technological innovation,taxes and financial subsidies,and infrastructure construction.Benchmarking the policies of international automotive industry powers provides a reference and basis for integrating their experiences in the formulation of China's automotive industry policy.Second,beginning with China's“Automotive Industry Policy”issued in 1994,the key automotive industry policies at different points in history and under different strategies are analyzed.Through policy adjustment and target setting,the changing focus through the historical development of China's automotive industry is determined,along with the development of the industry and technological progress.Then,from the perspectives of strategic planning,promotion and application,credit management,infrastructure,management standards,and standard systems,the advantages and disadvantages of current development policies for new energy and intelligent connected vehicles are clarified.The challenges and limitations of China's automotive industry policy are summarized,including a lack of investment in technology research and development,low level of infrastructure support,and insufficient consumer protection.China's automotive industry policy is then into three different historical stages:i)1994 to 2008,ii)2009 to 2013,and iii)2014 to present;and the characteristics of each stage are summarized.Finally,based on China's national conditions and considering the future development trends of the international automotive industry,the study concludes that under the strong drivers of carbon peak and neutrality goals,China's future automotive industry policy should feature energy saving and emission reduction as the main goals.Independent innovation should be the main enabler,strengthening and supplementing the supply chain through intelligent connectivity.