## 3 Results
### RPP and RPA Combination Indicator  
If one takes the calculated RPP and RPA values of a company as its X-Y coordinate, it clearly shows that the innovation ability (i.e., RPP) and innovation advantage (i.e., RPA) among several patent assignees can be easily compared. Maps in Figure 2a-c show different coordination values of six patent assignees' with respect to three technology fields of interests.  
Figure 2a shows that LG Chem. and Samsung SDI had much higher innovation leadership and better innovation advantage than the Japanese ones in the additives technology. It means that two Korean companies have shown great innovation ability in receiving their patents and led other competitors. Apparently, this is expected to be closely related to the patenting activity and invested R&D resources. It also represents the development of additives technology is more important for Korean companies. Although four Japanese firms had a lower patent position, Ube and Mitsubishi Chem. show the same great innovation advantage as Korean patent assignees for developing additives. Figure 2b illustrates the patenting activities of Sony, Mitsubishi Chem., and Panasonic demonstrate a much better innovation advantage with a higher leading position in lithium salts technology. It further indicates that their lithium salts technologies were significant. It is worth mentioning that Samsung SDI and LG Chem. had a higher innovation leadership but shows a weaker innovation advantage than Japan. Figure 2c depicts that in the Japanese companies, Sony and Panasonic had a better advantage in organic solvents. It means that the organic solvents technology of Sony and Panasonic were considerable. Samsung SDI also had higher innovation leadership and a better innovation advantage in organic solvents technology.  
With another point of view for Figure 2a-c, it can be discovered that six patent assignees had different patenting performance in developing electrolyte materials. For example, Ube and LG Chem. show a better advantage in additives, Mitsubishi Chem. and Sony were good at lithium salts, and Sony and Samsung SDI outperformed in solvents. Especially Sony had both better innovation advantages in technology of lithium slats and solvents among the six patent assignees. It is interesting to note that the Korean companies had a higher leading position in the three considered technologies than Japanese ones. This result was the same as the issued patent count analysis, which shows Samsung SDI and LG Chem. had more dominant positions than the Japanese companies. It is worth mentioning that one company with a higher leadership did not always show better innovation. Samsung SDI, for example, had the most patents in lithium salts technology and did not show a better innovation advantage than other firms. In contrast, one company with a lower patent position did not necessarily show a worse technology advantage. Sony is an example with a lower patent position but better innovation advantage in lithium salts technology.  
Figure 2: Revealed patent advantage (RPA) and relative patent position (RPP) analysis of six companies based on three technological fields: (**a**) H01M10/0567 (additives), (**b**) H01M10/0568 (lithium salts), and (**c**) H01M10/0569 (solvents). For the purpose of clarity, only their RPA values were noted for easier comparison.