Regional distribution of global patents for power lithium-ion batteries
(1) Strength distribution
Patent applicants generally first apply for a patent in their home country, and then use the priority to apply for a foreign patent within one year. Therefore, the distribution of the number of countries to which patent applicants have priority reflects the technical strength of each country in this field. From the national distribution of priority patent applications, it is reflected that the power-type lithium-ion battery technology is mainly concentrated in Japan, the United States, Germany, China and South Korea. Among them, Japan basically monopolized most of the industrial technology, and the number of priority patents reached 9,195, accounting for 65%. The United States has 1,260 related patent families, accounting for 9%, ranking second. There are 981 related patent families in China, accounting for 7%, ranking fourth, behind South Korea and close to Germany, which ranks fifth.
Figure 1 shows the trend chart of the top 5 national patent applications in priority countries. Patents in Japan and the United States started early, especially the large scale of Japanese patents. The situation is similar in Germany, China, and South Korea, which have developed rapidly in recent years.
(2) Patent layout
Japan and the United States are the countries with the largest patent families of power lithium-ion batteries, and their competition for the world market is also very fierce. Therefore, in addition to patent protection in the home country, in order to produce and sell products abroad, it must apply for relevant patents in foreign regions in order to obtain intellectual property protection, and the application of the same family of patents in the country can also reflect its market strategy.
As can be seen from Figure 2, in addition to applying in its own country, Japan focuses on the US and Chinese markets, and applies for a large number of PCT patents at the same time. The US patent layout is extensive and focuses on the Chinese market. China, South Korea, and Germany have little difference in the total number of patent applications, but there are differences in patent protection strategies between countries. Germany and South Korea focus on major foreign markets while protecting their domestic patents, and have a certain number of PCT patents; while China mainly targets its domestic market and has few patents in foreign markets. It should be noted that Japan has a total of 601 patents in China, 139 in the United States, 143 in South Korea, and 26 in Germany.
(3) Distribution of technical fields in major countries
It can be seen from Figure 3 that Japan occupies a leading position in various branch technologies, and has the most comprehensive technology development. The situation in the United States, China, South Korea, and Germany is relatively close. From Figure 4, it can be seen that the branch technical fields that countries pay attention to have a certain degree of similarity, but there are also differences. Japan pays the most attention to electrode technology, the United States pays attention to cell and battery pack technology, South Korea pays attention to cell and electrode technology, and China and Germany pay the most attention to cell technology.