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Ultra-thick, dense alloy-type anodes are promising for achieving large areal and volumetric performance in potassium-ion batteries (PIBs), but severe volume expansion as well as sluggish ion and electron diffusion kinetics heavily impede their widespread application. Herein, we design highly dense (3.1 ​g ​cm−3) Ti3C2Tx MXene and graphene dual-encapsulated nano-Sb monolith architectures (HD-Sb@Ti3C2Tx-G) with high-conductivity elastic networks (1560 ​S ​m−1) and compact dually encapsulated structures, which exhibit a large volumetric capacity of 1780.2 ​mAh cm−3 (gravimetric capacity: 565.0 ​mAh g−1), a long-term stable lifespan of 500 cycles with 82% retention, and a large areal capacity of 8.6 ​mAh cm−2 (loading: 31 ​mg ​cm−2) in PIBs. Using ex-situ SEM, in-situ TEM, kinetic investigations, and theoretical calculations, we reveal that the excellent areal and volumetric performance mechanism stems from the three dimensional (3D) high-conductivity elastic networks and the dual-encapsulated Sb architecture of Ti3C2Tx and graphene; these effectively mitigate against volume expansion and the pulverization of Sb, offering good electrolyte penetration and rapid ionic/electronic transmission. Ti3C2Tx also decreases the K+ diffusion energy barrier, and the ultra-thick compact electrode ensures volumetric and areal performance. These findings provide a feasible strategy for fabricating ultra-thick, dense alloy-type electrodes to achieve high areal and volumetric capacity energy storage via highly-dense, dual-encapsulated architectures with conductive elastic networks.

In recent years, with the rapid development of China’s economy, high haze industries such as thermal power industry in the Beijing–Tianjin–Hebei region have been over concentrated, and the environmental pollution is becoming more and more serious. The formulation and implementation of various policies play a crucial role in the coordinated development of high haze industries such as thermal power industry and economy in the Beijing–Tianjin–Hebei​ region. Based on the supply and demand matching for policies related to the coordinated development of high haze industries such as thermal power industry and economy in the Beijing–Tianjin–Hebei region, the paper constructs the matching model relevant to the issue as mentioned above, and the evaluation index system of fiscal policy, tax, finance, technology, and public policy through literature analysis and variance analysis, with an aim to analyze the matching degree of policy supply and demand. The results show that: the fiscal policy matches very well, the tax policy matches well, the financial policy and the technology policy barely match, and the matching of public service policy is out of balance. According to the supply and demand matching for policies related to the coordinated development of high haze industries such as thermal power industry and economy in the Beijing–Tianjin–Hebei region, the paper puts forward some suggestions for optimizing the following aspects: strengthening the financial investment policy, perfecting the tax types, deepening the green credit policy, strengthening the technical cooperation policy, and improving the monitoring and warning policy in Beijing, Tianjin, and Hebei. It aims to help promote industrial transformation and upgrading and realize the high-quality economic development in the Beijing–Tianjin–Hebei region.

With the accelerating urbanization process in China, the extensive economic growth model with high energy consumption and high pollution aggravates atmospheric environmental pollution and restricts the sustainable development of the social economy. The Beijing–Tianjin–Hebei region has the most severe haze pollution and the most acute contradiction between resources, environment and economic development. Based on the physical coupling theory, this paper constructs a coupling coordination degree model of the economy, environment and high haze pollution industries, such as the thermal power industry. Through literature analysis and expert investigation of the economic, industrial and environmental data of the Beijing–Tianjin–Hebei region from 2006 to 2018, the coordinated development of the economy, environment and high haze pollution industries, such as the thermal power industry, in the above region, was dynamically monitored. The monitoring results show that the development level of the Beijing, Tianjin and Hebei region is significantly different, and the three subregions have not entered the stage of coordinated development. Moreover, since 2015, they have been in a bottleneck period of development and have not achieved a higher level of progress. The three subregions have different advantages and restraining factors. For example, the backward level of Hebei’s economy and high haze pollution industries, such as the thermal power industry, restrict the coordinated development of the region as a whole. Only by accelerating the high-quality development of the Hebei economy can we break through the bottleneck of the development of Beijing, Tianjin and Hebei.