Abstract:    In the context of Sino-US trade disputes, the main challenge facing China′s manufacturing upgrading is the “neck-jamming” problem in the key and core technology fields, which is rooted in the “technology lock-in” strategy implemented by the first-mover countries such as the United States, Japan, and the European countries to the later-mover countries. Moreover, technology trajectory lock-in is one of those forms. How to identify the strategic layout of foreign technology trajectory lock-in as soon as possible and adopt an effective cracking strategy in time is of great significance for breaking through “neck-jamming” technology, promoting the process of upgrading China′s manufacturing industry, and maintaining national industrial security.Based on the situation of manufacturing upgrading in China, this paper proposed a recognition and analysis framework and a cracking path of foreign technology trajectory lock-in from the perspective of the patent citation network. Firstly, based on the collected patents data, the patent citation network was constructed by Matlab and Pajek software, and the technical trajectory—the main path of the maximum connected graph was identified and extracted by the main path SPC algorithm. Then, focusing on the index of “technology origin country”, the characteristics of technology trajectory were described in detail by using integral and local atlas analysis. Finally, based on the measurement of the patent fragmentation index, the organizational breakthrough strategy of foreign technology trajectory lock-in was proposed from the perspective of patent concentration strategy.The following conclusions were drawn from this research: firstly, the technological evolution trajectory of lithium battery separators technology has experienced two stages, including the main trajectory lock-in in the early stage (from 1976 to 2004) and the diversified development path of four sub-trajectories in the late stage (from 2005 to 2020). The latter two sub-trajectories were fused, which verified Barsala′s theory of technology evolution tree and indicated that the technology trajectory identification method adopted in this paper was applicable and can be extended to other technology fields for technology trajectory identification and extraction.Secondly, focusing on the index of “technology origin countries”, countries that have made technical contributions to the evolution and development of lithium battery separators technology mainly include Japan, the United States, and South Korea. Although Chinese patents have appeared in the sub-trajectory of technology, China, as the source country of technology, has not yet appeared on the main path. This verified the fact that China′s lithium battery separators technology field was locked by foreign technology as reported in Science and Technology Daily, indicating that the analytical framework of foreign technology trajectory lock-in proposed in this paper is effective and reliable, and can be extended to other technology fields to identify and analyze foreign technology trajectory lock-in.Thirdly, the patent fragmentation index was used to measure the patent concentration source. It was found that China′s patent fragmentation index has continued to rise in the past decade, far higher than the United States, Japan, and South Korea in the technological trajectory, which suggested that much of China′s patent resources are currently in extreme fragmentation, so the breakthrough strategy of organization mode based on patent concentration strategy was proposed.The main contributions of this paper are as follows. On the one hand, this paper put the technical trajectory lock-in with manufacturing upgrading into the same analytical framework. Based on the overall map and local map meticulous analysis, the characteristics of technological trajectory were described in detail, which provided the possibility for the early identification of foreign technology lock-in in the context of China′s manufacturing upgrade. On the other hand, on the basis of using the patent fragmentation index to measure the patent concentration degree of the first-mover countries on the technology trajectory, the patent concentration strategy was used as an organizational method to lock in technology breakthroughs, which made the path of lock cracking more distinct, with both theoretical robustness and practical operability.

Key words: foreign technology trajectory lock-in, manufacturing upgrading, main path analysis, patent aggregation strategy, lithium battery separators technology